JP2020177907A - Conductive composition, metallized substrate and method for producing the same - Google Patents

Abstract

To provide a conductive composition capable of forming a conductive part having high adhesiveness to a ceramic substrate.SOLUTION: There is provided a conductive composition prepared by combining composite particles of Ag and Pd (A), glass particles (B) and a metal component (C) composed of an Mn component (C1), an Fe component (C2), a Cu component (C3) and a Ti component (C4) and adjusting the ratio of the Ti component to 0.05 to 0.85 pt.mass based on 100 pts.mass of the composite particles (A) in terms of Ti element. The ratio of Pd is approximately 1 to 9 mass% based on the total amount of Ag and Pd in the composition. The glass particles (B) may contain borosilicate glass particles.SELECTED DRAWING: None

Description

The present invention relates to a conductive composition used for forming a circuit on a ceramic substrate in the field of electronics, a metallized substrate having a circuit formed of this composition, and a method for producing the same.

The conductive composition (conductive paste) is widely used in the electronics field because various patterns such as electrodes can be easily formed by printing or the like. Silver paste containing silver in conductive metal powder is used to form electrodes and circuits for electronic parts, etc., but silver is sulfided by sulfurous gas in the air, causing the electrodes to break or discolor. It is known that adding palladium to silver prevents sulfurization.

In addition, electronic components are required to have high reliability regardless of changes in the usage environment, and have sulfur resistance, high adhesion, plating resistance, solder resistance, and reliability (for use in harsh environments). There is a demand for a conductive paste that satisfies all the characteristics such as (withstandable adhesion).

Japanese Patent Application Laid-Open No. 59-132502 (Patent Document 1) describes a composition for forming a conductive film containing glass powder and silver powder composed of granular silver powder and flake-shaped silver powder as a conductive component and a small amount of palladium powder. Is disclosed.

Japanese Patent Application Laid-Open No. 59-132503 (Patent Document 2) contains silver powder and at least one selected from the group consisting of palladium powder, palladium oxide powder and silver-palladium alloy powder as a conductive component for forming a conductive film. The composition is disclosed.

According to Japanese Patent Application Laid-Open No. 59-155989 (Patent Document 3), sulfide is prevented by blending a titanate-based coupling agent with a conductive paste containing silver powder and palladium powder as conductive components, and the paste is contained. A composition for forming a conductive film in which the aggregation of palladium is suppressed is disclosed.

Japanese Unexamined Patent Publication No. 2004-250308 (Patent Document 4) discloses a conductive paste containing silver powder, palladium powder, and copper powder as conductive components and containing glass powder. Using lead-free SiO _2- Bi-Ba-based lead-free alkali-free glass, electrodes having good acid resistance, sulfurization resistance, and solder wettability have been obtained. In the examples, a conductive paste containing spherical silver powder, flaky silver powder, copper powder, glass frit, and palladium powder is prepared.

However, in Patent Documents 1 to 4, reliability is not evaluated.

Japanese Patent Application Laid-Open No. 7-302510 (Patent Document 5) describes fine spherical silver powder, coarse-grained spherical silver powder, or coarse-grained spherical silver powder as a conductive paste that can prevent the generation of cracks and the exudation of glass when the electrode and the resistor are simultaneously fired. A conductive paste composition containing spherical silver-coated nickel and flake-shaped silver powder and flake-shaped silver powder as conductive components is disclosed. The document states that palladium may be added to prevent the sulfurization of silver. Further, it is described that copper or copper oxide may be added as a glass frit or an inorganic binder in order to increase the adhesive strength between the substrate and the electrode.

However, with this composition, although no deterioration in physical properties is observed in the aging test at 150 ° C. for 24 hours, it cannot be said that the evaluation is sufficient for evaluating the reliability.

Japanese Patent Application Laid-Open No. 7-335402 (Patent Document 6) describes spherical silver powder having an average particle size of 0.1 to 0.5 μm and an average particle size of 0.5 to 1 as the conductive powder of the paste for the top electrode of the chip resistor. It is disclosed that the compactness of the fired film is improved in combination with a .5 μm spherical silver-coated palladium powder. This document describes the addition of copper and / or copper oxide as an inorganic binder in order to obtain high adhesive strength to the substrate.

However, even in this paste, since the proportion of palladium is high, there is a concern that the conductivity will be low and the cost will be high.

Japanese Patent Application Laid-Open No. 2010-532586 (Patent Document 7) discloses a paste in which silver powder and silver-palladium co-precipitated powder are combined as a conductor paste for a ceramic substrate to be fired at 650 ° C. or lower.

However, this paste is not compatible with baking at high temperatures.

JP-A-59-132502 (Claims) JP-A-59-132503 (Claims) JP-A-59-155989 (Claims, upper right column, pages 11-18) JP-A-2004-250308 (Claim 2, paragraph [0006], Examples) JP-A-7-302510 (Claims, paragraphs [0007] [0021] [0022], Examples) JP-A-7-335402 (Claim 1, paragraph [0009] [0018]) JP-A-2010-532586 (Claim 1, paragraph [0064], Examples)

Therefore, an object of the present invention is to provide a conductive composition capable of forming a conductive portion having high adhesion to a ceramic substrate, a metallized substrate having a conductive portion formed of this composition, and a method for producing the same. ..

Another object of the present invention is a conductive composition having high sulfurization resistance and capable of forming a conductive portion having high adhesion to a ceramic substrate regardless of changes in the usage environment, and a conductive portion formed of this composition. To provide a metallized substrate and a method for manufacturing the same.

Still another object of the present invention is to provide a conductive composition capable of producing a highly reliable metallized substrate, a metallized substrate having a conductive portion formed of the composition, and a method for producing the same.

As a result of diligent studies to achieve the above object, the present inventor has obtained composite particles (A) of silver (Ag) and palladium (Pd), glass particles (B), manganese (Mn) component (C1), and iron. A combination of a metal component (C) composed of a (Fe) component (C2), a copper (Cu) component (C3) and a titanium (Ti) component (C4), and the ratio of the Ti component in terms of Ti element is the composite. The present invention has been completed by finding that a conductive portion having high adhesion to a ceramic substrate can be formed by adjusting the particle (A) to 0.05 to 0.85 parts by mass with respect to 100 parts by mass.

That is, the conductive composition of the present invention is a conductive composition containing a composite particle (A) of Ag and Pd, a glass particle (B) and a metal component (C), and the metal component (C) is Mn component (C1), Fe component (C2), Cu component (C3) and Ti component (C4), and the ratio of the Ti component is 100 parts by mass of the composite particle (A) in terms of Ti element. It is 0.05 to 0.85 parts by mass. The ratio of Pd to the total amount of Ag and Pd is about 1 to 9% by mass. The glass particles (B) may contain borosilicate glass particles. The Ti component (C4) may be an inorganic Ti compound. The conductive composition preferably does not contain Ag particles.

The present invention also comprises a method for producing a metallized substrate, which comprises a bonding step of adhering the conductive composition to the ceramic substrate and a firing step of firing the conductive composition adhered to the ceramic substrate to form a conductive portion. included. In the firing step, the conductive composition may be fired in air.

The present invention also includes a metallized substrate obtained by the above-mentioned manufacturing method. The ceramic substrate may be an alumina substrate, an alumina-zirconia substrate, an aluminum nitride substrate, a silicon nitride substrate, or a silicon carbide substrate.

In the present specification and claims, the term "metal component" is used to include a simple substance of a metal and a metal compound. The same applies to the Mn component, Fe component, Cu component and Ti component.

In the present invention, a metal component (A) composed of Ag and Pd composite particles (A), glass particles (B), Mn component (C1), Fe component (C2), Cu component (C3) and Ti component (C4) ( In combination with C), the ratio of the Ti component is adjusted to 0.05 to 0.85 parts by mass with respect to 100 parts by mass of the composite particle (A) in terms of Ti element, so that the ratio with respect to the ceramic substrate is adjusted. It is possible to form a conductive portion having high adhesion. Further, when the ratio of Pd is adjusted to a specific ratio, it is possible to form a conductive portion having high sulfurization resistance and high adhesion to the ceramic substrate regardless of changes in the usage environment. Further, it exhibits excellent conductivity, can maintain high adhesion to a ceramic substrate even under harsh conditions such as high temperature and high humidity and sudden temperature change, and can manufacture a highly reliable metallized substrate.

[Composite particle (A)]
The conductive composition of the present invention contains composite particles (A) of Ag and Pd.

The composite particles may contain Ag and Pd as metal components and may contain unavoidable impurities such as those derived from a production method, but it is preferable that Ag and Pd are contained as main components. The total ratio of Ag and Pd in the composite particles may be 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass (Ag and Pd only) is particularly preferable. ..

The Pd content in the composite particles may be adjusted so that the ratio of Pd to the total amount of Ag and Pd in the conductive composition is about 0.1 to 10% by mass. The ratio of Pd is, for example, 1 to 9% by mass (for example, 2 to 8% by mass), preferably 3 to 7.5% by mass (for example, 5 to 7.) With respect to the total amount of Ag and Pd in the conductive composition. The Pd content in the composite particles may be adjusted so as to be 5% by mass), more preferably 3 to 7% by mass (particularly 4 to 6% by mass). If the proportion of Pd is too small, the sulfurization resistance may decrease, and if it is too large, the adhesion to the ceramic substrate may decrease.

The composite form of the composite particles is not particularly limited, and may be an alloy particle of Ag and Pd, a coprecipitated particle of Ag and Pd, a Pd particle coated with Ag, an Ag particle coated with Pd, and the like.

Examples of the coprecipitated particles include powder in which Ag particles and Pd particles are uniformly mixed and aggregated, and particles having a double layer structure in which Ag particles or Pd particles are aggregated to form a core portion.

Examples of the Ag-coated Pd particles include Pd particles or Pd alloy particles whose surface is partially coated with Ag. Examples of the Pd-coated Ag particles include Ag particles or Ag alloy particles whose surface is partially coated with Pd. Examples of other metals for forming an alloy in the Pd alloy particles include Mn, Fe, Cu, Ag, and Pt. Examples of other metals for forming an alloy in the Ag alloy particles include Mn, Fe, Cu, Pd, and Pt.

The shape of the composite particle is, for example, spherical (true spherical or substantially spherical), ellipsoidal (elliptical sphere), polyhedral (polyhedral pyramid, cubic or rectangular parallelepiped, etc.), rod-shaped or rod-shaped, Examples include fibrous, dendritic, and irregular shapes. Of these, granules such as spherical, elliptical, polyhedral, and indefinite are preferable from the viewpoint of improving adhesion to the ceramic substrate, and spherical or regular polyhedron (regular hexahedron or cube, regular octahedron, etc.). An isotropic shape (particularly spherical) such as is particularly preferable.

In the present specification and claims, "spherical" is used to mean both true spherical and substantially spherical. In the sphere, the ratio of the major axis to the minor axis is, for example, 1-2, preferably 1-1.5, more preferably 1-1.3, more preferably 1-1.2, most preferably 1-1.1. Is.

The particle size of the composite particles is not particularly limited and can be selected from the range of about 0.1 to 30 μm as the central particle size (D50), and the central particle size is, for example, 0.2 to 10 μm, preferably 0.3 to 5 μm. More preferably, it is about 0.5 to 3 μm (particularly 0.8 to 2 μm). If the central particle size is too small, the adhesion to the ceramic substrate may decrease, and conversely, if it is too large, the adhesion may decrease as well.

In the present specification and claims, the central particle size of particles (including other particles described later) is the average particle size (volume basis) measured using a laser diffraction / scattering type particle size distribution measuring device. means.

The proportion of the composite particles (A) can be selected from the range of about 10 to 99% by mass in the conductive composition, for example, 30 to 98% by mass, preferably 50 to 95% by mass (for example, 50 to 92% by mass), and further. It is preferably about 70 to 90% by mass (particularly 80 to 90% by mass). If the proportion of the composite particles (A) is too small, the conductivity and sulfurization resistance may decrease, and if the proportion is too large, the adhesion to the ceramic substrate may decrease.

[Glass particles (B)]
The glass particles (glass powder) (B) may function as a sintering aid, and conventional glass particles used for a conductor can be used.

The composition of the glass constituting the glass particles (B) is not particularly limited, but for example, the composition formula SiO _2- B ₂ O _3- MO-R ₂ O (in the formula, M represents an element other than Si and B). , R indicates an alkali metal such as K and Na), borosilicate glass (silica-based glass), composition formula Al ₂ O ₃ -SiO _2- MO-R ₂ O (in the formula, M is Al). Aluminosilicate glass represented by (R is the same as above), composition formula Al ₂ O ₃ −SiO ₂ −B ₂ O ₃ −MO-R ₂ O (in the formula, M is Al). , Si, indicates an element other than B, R is the same as above), aluminoborosilicate glass, composition formula Bi ₂ O _3- B ₂ O _3- MO (in the formula, M is other than Bi, B) Examples thereof include bismuth-based glass represented by (indicating an element) and zinc-based glass represented by ZnO-SiO _2- MO (where M represents an element other than Zn and Si). These glasses can be used alone or in combination of two or more. Of these, borosilicate glass and zinc-based glass are preferable, and borosilicate glass is particularly preferable, from the viewpoint of improving plating resistance. Glass particles having these glass compositions can also be used alone or in combination of two or more.

The softening point (or melting point) of the glass particles (B) is preferably a temperature lower than the firing temperature of the conductive composition. The softening point of the glass particles is, for example, 400 to 800 ° C., preferably 420 to 800 ° C., more preferably 450 to 800 ° C., more preferably 500 to 800 ° C., and most preferably about 550 to 790 ° C. If the softening point is too low, the strength of the fired body may decrease, and if it is too high, the melt fluidity may decrease, so that the function as a binder may decrease.

The shape of the glass particles (B) is the same as that of the composite particles (A), including a preferred embodiment.

The central particle size (D50) of the glass particles (B) is, for example, 0.1 to 20 μm, preferably 0.5 to 10 μm, and more preferably about 1 to 5 μm. If the particle size is too small, the economy may be lowered and the dispersibility in the composition may be lowered. On the contrary, if the particle size is too large, the printability and the uniformity of the fired film are deteriorated, and when printing with a mesh screen, it may cause mesh clogging.

The ratio of the glass particles (B) can be selected from the range of about 0.05 to 10 parts by mass with respect to 100 parts by mass of the composite particles (A), for example, 0.1 to 5 parts by mass, preferably 0.3 to 3 parts. It is about 0.4 to 2 parts by mass (particularly 0.5 to 1.5 parts by mass) by mass. If the proportion of the glass particles (B) is too small, the function as a sintering aid may be lowered and the effect of improving the plating resistance may be lowered, and conversely, if the proportion is too large, the conductivity may be lowered. is there.

[Metal component (C)]
The metal component (C) is composed of a combination of an Mn component (C1), an Fe component (C2), a Cu component (C3), and a Ti component (C4). In the present invention, when the conductive composition contains this metal component (C), the denseness of the fired body can be improved, and the reliability of the conductive portion of the fired body can be improved.

(Mn component (C1))
The Mn component (C1) includes a simple substance of Mn, an inorganic Mn compound, and an organic Mn compound.

Examples of the inorganic Mn compound include Mn oxides such as manganese dioxide; manganese boride; manganese carbonate, manganese phosphate, manganese borate, manganese sulfate, manganese nitrate and other inorganic acid Mn salts; and manganese chloride and other Mn halides. And so on. These inorganic Mn compounds can be used alone or in combination of two or more.

The shapes of Mn alone and the inorganic Mn compound are the same as those of the composite particles (A), including preferred embodiments.

The central particle size (D50) of the particles formed of Mn alone and the inorganic Mn compound is, for example, 0.1 to 30 μm, preferably 1 to 20 μm, and more preferably about 3 to 15 μm. If the particle size is too small, the economy may be lowered and the dispersibility in the conductive composition may be lowered. On the contrary, if the particle size is too large, the printability and the uniformity of the fired film are deteriorated, and when printing with a mesh screen, it may cause mesh clogging.

Examples of the organic Mn compound include manganese formate, manganese acetate, manganese oxalate, manganese butyrate, manganese caproate, manganese octylate, manganese neodecanoate, manganese stearate, manganese naphthenate and other carboxylic acid Mn salts. The organic Mn compound may be a Mn-based metal soap (for example, a higher fatty acid Mn salt such as manganese octylate, manganese neodecanoate, or manganese stearate). These organic Mn-based compounds can be used alone or in combination of two or more. Organic Mn compounds (particularly C _4-24 saturated fatty acid Mn salts) may be used in the form of liquid compositions. The liquid composition may be a hydrocarbon solution such as a petroleum-based hydrocarbon solution (for example, a mineral spirit solution).

As the Mn component (C1), an inorganic Mn compound and an organic Mn compound are preferable, Mn oxides such as manganese dioxide and C _4-24 saturated fatty acid Mn salts such as manganese octylate are more preferable, and C _6-12 saturated fatty acid Mn Salt is particularly preferred.

The ratio of the Mn component (C1) is, for example, 0.01 to 1 part by mass, preferably 0.03 to 0. With respect to 100 parts by mass of the composite particle (A) in terms of Mn element (as a ratio of Mn element). It is about 5 parts by mass, more preferably 0.1 to 0.3 parts by mass (particularly 0.15 to 0.25 parts by mass). If the proportion of the Mn component (C1) is too small, the compactness of the fired body may decrease, and if it is too large, the conductivity may decrease.

(Fe component (C2))
The Fe component (C2) contains a simple substance of Fe and an inorganic Fe compound.

Examples of the inorganic Fe compound include Fe oxides such as iron (II) oxide, iron (III) oxide (diiron trioxide), and triiron tetroxide; iron borate; iron hydroxide; iron sulfide; iron carbonate, Examples thereof include inorganic acid Fe salts such as iron phosphate, iron borate, iron sulfate and iron nitrate; and Fe halides such as iron chloride. These inorganic Fe compounds can be used alone or in combination of two or more.

The shapes of the Fe simple substance and the inorganic Fe compound are the same as those of the composite particle (A), including the preferred embodiment.

The central particle size (D50) of the particles formed of the Fe simple substance and the inorganic Fe compound is, for example, 0.1 to 10 μm, preferably 0.5 to 5 μm, and more preferably about 1 to 3 μm. If the particle size is too small, the economy may be lowered and the dispersibility in the conductive composition may be lowered. On the contrary, if the particle size is too large, the printability and the uniformity of the fired film are deteriorated, and when printing with a mesh screen, it may cause mesh clogging.

As the Fe component (C2), an inorganic Fe compound is preferable, and an Fe oxide such as ferric trioxide is particularly preferable.

The Fe component (C2) may contain an organic Fe compound (for example, a C _4-24 saturated fatty acid Fe salt such as iron octylate, an Fe complex such as Nasem ferric iron) in a trace amount. From the viewpoint of plating resistance, it is preferable that the organic Fe compound is substantially not contained, and it is particularly preferable that the organic Fe compound is not contained.

The ratio of the Fe component (C2) is, for example, 0.01 to 1 part by mass, preferably 0.03 to 0. With respect to 100 parts by mass of the composite particle (A) in terms of Fe element (as a ratio of Fe element). It is about 5 parts by mass, more preferably about 0.05 to 0.3 parts by mass (particularly 0.1 to 0.2 parts by mass). If the proportion of the Fe component (C2) is too small, the compactness of the fired body may decrease, and if it is too large, the conductivity may decrease.

(Cu component (C3))
The Cu component (C3) contains a simple substance of Cu and an inorganic Cu compound.

Examples of the inorganic Cu compound include Cu oxides such as copper oxide; copper hydroxide; copper sulfide; copper carbonate, copper phosphate, copper borate, copper sulfate, copper nitrate and other inorganic acid Cu salts; copper chloride and the like. Examples include Cu halides. These inorganic Cu compounds can be used alone or in combination of two or more.

The shapes of the Cu simple substance and the inorganic Cu compound are the same as those of the composite particle (A), including the preferred embodiment.

The central particle size (D50) of the particles formed of the Cu simple substance and the inorganic Cu compound is, for example, 0.1 to 10 μm, preferably 0.5 to 5 μm, and more preferably about 1 to 3 μm. If the particle size is too small, the economy may be lowered and the dispersibility in the conductive composition may be lowered. On the contrary, if the particle size is too large, the printability and the uniformity of the fired film are deteriorated, and when printing with a mesh screen, it may cause mesh clogging.

As the Cu component (C3), Cu alone and Cu oxide are preferable, and copper oxide is particularly preferable.

The Cu component (C3) may contain an organic Cu compound (for example, a carboxylic acid Cu salt such as copper naphthenate) as long as it is in a trace amount, but from the viewpoint of plating resistance, the organic Cu compound is substantially used. It is preferable not to contain the organic Cu compound, and it is particularly preferable not to contain the organic Cu compound.

The ratio of the Cu component (C3) is, for example, 0.01 to 1 part by mass, preferably 0.05 to 0. With respect to 100 parts by mass of the composite particle (A) in terms of Cu element (as a ratio of Cu element). It is about 5 parts by mass, more preferably 0.1 to 0.3 parts by mass (particularly 0.15 to 0.25 parts by mass). If the proportion of the Cu component (C3) is too small, the denseness of the fired body may decrease, and conversely, if it is too large, the conductivity may decrease.

(Ti component (C4))
The Ti component (C4) includes a simple substance of Ti, an inorganic Ti compound, and an organic Ti compound.

Examples of the inorganic Ti compound include Ti oxides such as titanium monoxide, titanium dioxide and dititanium trioxide; and Ti halides such as titanium tetrachloride. These inorganic Ti compounds can be used alone or in combination of two or more.

The shapes of the Ti simple substance and the inorganic Ti compound are the same as those of the composite particle (A), including the preferred embodiment.

The central particle size (D50) of the particles formed of the Ti simple substance and the inorganic Ti compound is, for example, 0.05 to 5 μm, preferably 0.1 to 1 μm, and more preferably about 0.2 to 0.5 μm. If the particle size is too small, the economy may be lowered and the dispersibility in the conductive composition may be lowered. On the contrary, if the particle size is too large, the printability and the uniformity of the fired film are deteriorated, and when printing with a mesh screen, it may cause mesh clogging.

Examples of the organic Ti compound include alkyl titanates (alkoxydotitanium) such as tetraisopropyl titanate, tetra n-butyl titanate, tetra t-butyl titanate, and tetraoctyl titanate; and acylates such as tetrastearyl titanate and tetraisostearyl titanate; Examples thereof include chelates such as titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetate acetate, titanium dodecylbenzenesulfonate compound, titanium phosphate ester titanium complex, and titanium lactate. These organic Ti compounds can be used alone or in combination of two or more.

As the Ti component (C4), tetra C _3-12 alkyl titanates such as an inorganic Ti compound and _tetraoctyl titanate are preferable, and an inorganic Ti compound is more preferable from the viewpoint of plating resistance. Further, among the inorganic Ti compounds, Ti oxide is preferable, titanium dioxide is more preferable, and rutile-type titanium dioxide is particularly preferable.

The ratio of the Ti component (C4) is, for example, 0.05 to 0.85 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the composite particle (A) in terms of Ti element (as a ratio of Ti element). 0.8 parts by mass, more preferably 0.2 to 0.7 parts by mass, more preferably 0.3 to 0.65 parts by mass, most preferably 0.4 to 0.6 parts by mass (particularly 0.5 to 0.6 parts). It is about 0.6 parts by mass). If the proportion of the Ti component (C4) is too small, the compactness of the fired body may decrease, and if it is too large, the conductivity may decrease.

(Ratio of metal component (C))
The ratio of the metal component (C) is 0.6 to 3.5 mass by mass with respect to 100 parts by mass of the composite particle (A) in terms of metal element (as the total ratio of Mn element, Fe element, Cu element and Ti element). It can be selected from a range of about parts, for example, 0.7 to 3.2 parts by mass (for example, 0.8 to 3 parts by mass), preferably 0.8 to 2.5 parts by mass, and more preferably 0.9 to 2 parts by mass. Parts, more preferably about 0.95 to 1.5 parts by mass (particularly about 1 to 1.3 parts by mass). If the proportion of the metal component (C) is too small, the denseness of the fired body may decrease, and if it is too large, the conductivity may decrease.

The ratio of the total amount of the Mn component (C1), the Fe component (C2) and the Cu component (C3) is 100 parts by mass of the composite particle (A) in terms of metal (as the total ratio of the Mn element, the Fe element and the Cu element). On the other hand, it can be selected from the range of about 0.1 to 2.9 parts by mass, for example, 0.2 to 2.5 parts by mass, preferably 0.3 to 2 parts by mass, and more preferably 0.4 to 1.5 parts by mass. Parts, more preferably about 0.45 to 1 part by mass (particularly 0.5 to 0.7 parts by mass).

[Resin component (D)]
The conductive composition of the present invention may further contain the resin component (D) as an organic binder. The resin component (D) is not particularly limited, and for example, a thermoplastic resin (olefin resin, vinyl resin, acrylic resin, styrene resin, polyether resin, polyester resin, polyamide resin, cellulose derivative). Etc.), thermosetting resins (thermosetting acrylic resins, epoxy resins, phenol resins, unsaturated polyester resins, polyurethane resins, etc.) and the like. These resin components can be used alone or in combination of two or more. Among these resin components, resins that are easily burned out in the firing process and have a low ash content, such as acrylic resins (polymethylmethacrylate, polybutylmethacrylate, etc.) and cellulose derivatives (nitrocellulose, ethylcellulose, butylcellulose, cellulose acetate) , Etc.), polyethers (polyoxymethylene, etc.), rubbers (polybutadiene, polyisoprene, etc.) and the like are widely used, and cellulose derivatives such as ethyl cellulose are preferable.

The ratio of the resin component (D) is, for example, 0.1 to 10 parts by mass, preferably 0.3 to 5 parts by mass, and more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the composite particle (A). (Especially 1 to 2 parts by mass). If the proportion of the resin component (D) is too small, the handleability of the conductive composition may decrease, and conversely, if it is too large, the denseness of the fired body may decrease.

[Organic solvent (E)]
The conductive composition of the present invention may further contain an organic solvent (E). The organic solvent (E) is not particularly limited, and can impart an appropriate viscosity to the conductive composition (particularly a paste-like composition) and can be easily volatilized by a drying treatment after the conductive composition is applied to the substrate. It may be an organic compound or an organic solvent having a high boiling point.

Examples of such organic solvents include aromatic hydrocarbons (paraxylene, ethylbenzene, trimethylbenzene, naphthalene, cumene, inden, etc.), aliphatic hydrocarbons (hexane, heptane, octane, nonane, etc.), esters (lactic acid). Ethyl, texanol, etc.), ketones (isophorone, etc.), amides (dimethylformamide, etc.), aliphatic alcohols (ethanol, isopropanol, butanol, octanol, 2-ethylhexanol, decanol, diacetone alcohol, etc.), cellosolves (methyl) Cellosolves, ethyl cellosolves, etc.), cellosolve acetates (ethyl cellosolve acetate, butyl cellosolve acetate, etc.), carbitols (carbitol, methylcarbitol, ethylcarbitol, butylcarbitol, etc.), carbitol acetates (ethylcarbitol acetate, etc.) , Butylcarbitol acetate), aliphatic polyhydric alcohols (ethylene glycol, diethylene glycol, dipropylene glycol, butanediol, triethylene glycol, glycerin, etc.), alicyclic alcohols [eg, cycloalkanols such as cyclohexanol; Terpen alcohols such as α-terpineol and dihydroterpineol (monoterpen alcohols, etc.)], aromatic alcohols (methacresol, etc.), aromatic carboxylic acid esters (dibutylphthalate, dioctylphthalate, etc.), nitrogen-containing heterocyclic compounds (Dimethylimidazole, dimethylimidazolidinone, etc.) and the like. These organic solvents can be used alone or in combination of two or more.

Among these organic solvents, aliphatic diol monocarboxylates such as texanol (2,2,4-trimethylpentane-1,3-diol monoisobutyrate) and octanol are considered from the viewpoint of fluidity of the conductive composition. Aliphatic alcohols such as, alicyclic alcohols such as terpineol, carbitols such as butyl carbitol, and carbitol acetates such as butyl carbitol acetate are preferable, and the aliphatic diol monocarboxylate and the carbitol acetates are used. The combination of is particularly preferable. When the aliphatic diol monocarboxylate and the carbitol acetates are combined, the mass ratio of the two is the former / the latter = 99/1 to 10/90, preferably 90/10 to 30/70, and more preferably 80. It is about / 20 to 50/50 (particularly 75/25 to 60/40). Further, as the organic solvent, hydrocarbons such as petroleum-based hydrocarbons (or mineral spirits) such as aromatic hydrocarbons and aliphatic hydrocarbons are preferable from the viewpoint of improving plating resistance.

The ratio of the organic solvent (E) can be selected from the range of about 0.01 to 50 parts by mass with respect to 100 parts by mass of the composite particle (A), for example, 1 to 30 parts by mass, preferably 3 to 20 parts by mass, and further. It is preferably about 5 to 15 parts by mass (particularly 8 to 13 parts by mass). When the organic solvent (E) contains a petroleum-based hydrocarbon, the ratio of the petroleum-based hydrocarbon is, for example, 0.01 to 30 parts by mass, preferably 0.05 to 20 parts by mass with respect to 100 parts by mass of the metal particles (A). It is by mass, more preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and most preferably 1 to 3 parts by mass. If the proportion of the organic solvent (E) is too small, the viscosity of the conductive composition may increase and the handleability and plating resistance may decrease. On the contrary, if the proportion of the organic solvent (E) is too large, the denseness of the fired body may decrease. There is.

[Other metal-containing components (F)]
The conductive composition of the present invention may further contain a metal-containing component (other metal-containing component) (F) other than the composite particles (A), the glass particles (B), and the metal component (C). Good.

The other metal-containing component (F) was selected from the group consisting of, for example, Ag, Pd, Al, Mn, Fe, Ni, Cu, Mo, W, Pt, Au, Co, Ti, Zr, Sn and the like. Examples thereof include a metal component of a metal element (elemental metal, a metal compound), an alloy of two or more kinds of metal elements selected from the above group, or a composite metal compound.

The shape of the other metal-containing component is the same as that of the composite particle (A), including the preferred embodiment.

The particle size of the particles formed by the other metal-containing component (F) is not particularly limited, and the center particle size (D50) can be selected from the range of about 0.5 to 30 μm, and the center particle size is, for example, 1 to 1. It is about 10 μm, preferably 1 to 4 μm, and more preferably 1.5 to 3 μm (particularly 1.5 to 2.5 μm). If the central particle size is too small, the adhesion to the ceramic substrate may decrease, and conversely, if it is too large, the adhesion may decrease as well.

The ratio of the other metal-containing component (F) may be about 5 parts by mass or less (for example, 0.01 to 5 parts by mass) with respect to 100 parts by mass of the composite particle (A) in terms of metal element.

From the viewpoint of improving the plating resistance, the conductive composition of the present invention preferably does not substantially contain Ag particles (particularly spherical Ag particles) as other metal-containing component (F), and Ag particles (particularly, spherical Ag particles) are preferably contained. In particular, it is particularly preferable that it does not contain spherical Ag particles).

[Conventional Additives]
The conductive composition of the present invention may further contain conventional additives as long as the effects of the present invention are not impaired. Conventional additives include, for example, hardeners (hardeners for acrylic resins, etc.), colorants (dye pigments, etc.), hue improvers, dye fixers, gloss enhancers, metal corrosion inhibitors, stabilizers (oxidation). Inhibitors, UV absorbers, etc.), Surfactants or Dispersants (Anionic Surfactants, Cationic Surfactants, Nonionic Surfactants, Amphoteric Surfactants, etc.), Dispersion Stabilizers, Viscosity Adjusters or Examples include rheology modifiers, moisturizers, thixotropic agents, leveling agents, defoamers, bactericides, fillers and the like. These other ingredients can be used alone or in combination of two or more. The total ratio of the conventional additives can be selected according to the type of the component, and is usually about 10 parts by mass or less (for example, 0.01 to 10 parts by mass) with respect to 100 parts by mass of the composite particle (A).

[Method for preparing conductive composition]
As a method for preparing the conductive composition (or conductive paste) of the present invention, a method of mixing using a conventional mixer or the like can be used in order to uniformly disperse each component, and an apparatus having a pulverizing function (for example). , 3 rolls, mortar, mill, etc.) may be used. The method of adding each component may be a method of collectively adding and mixing, or a method of dividing and adding and mixing.

[Metalized substrate and its manufacturing method]
The metallized substrate (ceramic substrate with a conductive portion such as a wiring circuit board) of the present invention has a bonding step of adhering the conductive composition to the ceramic substrate, and the conductive composition adhered to the ceramic substrate is fired to form the conductive portion. It is obtained through a firing step of forming.

In the present invention, when the metal component (C) is an organometallic compound, the organometallic compound may be added in the form of a liquid composition from the viewpoint of improving the plating resistance, and at least the Mn component (C1) may be added. ) And / or the Ti component (C4) is preferably added in the form of a liquid composition, and the Mn component (C1) is particularly preferably added in the form of a liquid composition.

In the bonding step, the method of bonding the conductive composition can be selected according to the type of the metallized substrate. In the surface metallized substrate and the through-hole wall surface metallized substrate, the conductive composition is formed on the surface of the substrate and the inner wall of the through hole (through hole). An object may be applied, and in the via-filled substrate, the conductive composition may be filled (via-filled) in the front and back through holes.

As a method for forming a coating film using a conductive composition, conventional coating methods such as flow coating method, dispenser coating method, spin coating method, spray coating method, screen printing method, flexographic printing method, casting method, etc. A bar coating method, a curtain coating method, a roll coating method, a gravure coating method, a dipping method, a slit method, a photolithography method, an inkjet method, etc. can be used. In the coating method, a pattern may be formed (drawn) with a coating film, and a pattern (sintered film, metal film, sintered body layer, conductor layer) is formed by drying the formed pattern (drawing pattern). it can. The drawing method (or printing method) for drawing the pattern (coating layer) is not particularly limited as long as it is a printing method capable of forming a pattern, and for example, a screen printing method, an inkjet printing method, or an intaglio printing method (for example,). Gravure printing method, etc.), offset printing method, intaglio offset printing method, flexo printing method, etc. Of these, the screen printing method is preferable.

Examples of the material of the ceramic substrate include metal oxides (alumina or aluminum oxide, zirconia, sapphire, ferrite, zinc oxide, niobium oxide, murite, beryllia, etc.), silicon oxide (quartz, silicon dioxide, etc.), and metal nitrides (metal nitrides, etc.) Aluminum nitride, titanium nitride, etc.), silicon nitride, boron nitride, carbon nitride, metal carbides (titanium carbide, tungsten carbide, etc.), silicon carbide, boron carbide, metal compound oxide [metal salt (barium titanate, titanic acid) Strontium, lead titanate, niobium titanate, calcium titanate, magnesium titanate, etc.), metal zirconate salts (barium zirconate, calcium zirconate, lead zirconate, etc.), etc.] and the like. These ceramics can be used alone or in combination of two or more.

Among these ceramic substrates, alumina substrates, alumina-zirconia substrates, aluminum nitride substrates, silicon nitride substrates, and silicon carbide substrates are preferable from the viewpoint of high reliability in the field of electricity and electronics, and alumina substrates, aluminum nitride substrates, and silicon nitride substrates are preferable. Is particularly preferable.

The thickness of the ceramic substrate may be appropriately selected depending on the intended use, and is, for example, 0.001 to 10 mm, preferably 0.01 to 5 mm, and more preferably 0.05 to 3 mm (particularly 0.1 to 1 mm). You may.

The atmosphere in firing is preferably in air. The firing temperature may exceed the softening point of the glass particles in the conductive composition, and is, for example, 600 to 1100 ° C., preferably 700 to 1000 ° C., and more preferably about 800 to 950 ° C. The firing time is, for example, 1 minute to 3 hours, preferably 10 minutes to 2 hours, and more preferably about 30 minutes to 1.5 hours.

The firing (particularly firing in a nitrogen atmosphere) may be performed using a batch furnace or a belt-conveying tunnel furnace.

The metallized substrate of the present invention is excellent in conductivity, and the resistance value of the conductive portion may be 10 μΩ · cm or less (for example, 2 to 6 μΩ · cm).

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the following examples, the materials used in the examples, the evaluation substrate obtained in the examples, and the evaluation method of the obtained substrate are shown below.

[Material used]
(AgPd particles)
AgPd particles A (Pd5%) ... Alloy particles of Ag and Pd (mass ratio of Ag and Pd: Ag / Pd = 95/5), spherical, central particle size D50: about 1.2 μm, specific surface area 1.1 m ² / g
AgPd particles B (Pd10%) ... Alloy particles of Ag and Pd (mass ratio of Ag and Pd: Ag / Pd = 90/10), spherical, central particle size D50: about 1.4 μm, specific surface area 1.0 m ² / g
AgPd particles C (Pd30%) ... Alloy particles of Ag and Pd (mass ratio of Ag and Pd: Ag / Pd = 70/30), spherical, central particle size D50: about 1.4 μm, specific surface area 1.1 m ² / g
AgPd particles D (Pd1%) ... Alloy particles of Ag and Pd (mass ratio of Ag and Pd: Ag / Pd = 99/1), spherical (Ag particles)
Spherical Ag particles (2 μm) ... Center particle size D50: Approximately 2 μm, specific surface area 0.42 m ² / g
(Glass particles)
Silica-based glass particles: Composition SiO _2- B ₂ O _3- RO, softening temperature 780 ° C.
Zinc-based glass particles: Composition ZnO-SiO _2- B ₂ O _3- RO, softening temperature 575 ° C
Bismuth-based glass particles: Composition Bi ₂ O _3- ZnO-B ₂ O ₃ , softening temperature 490 ° C.
(Metal component)
Manganese oxide (MnO) particles: Purity 3N, average particle size about 1 μm
Mn-based metal soap (manganese octylate) ... Manganese octylate (II) mineral spirit solution, manganese content 8% by mass
Iron oxide (Fe ₂ O ₃ ) particles ... Purity 2N, average particle size about 1 μm
Copper oxide (CuO) particles: Purity 3N, average particle size about 1 μm
Titanium dioxide (TiO ₂ ) particles: Spherical, average particle size of about 0.25 μm
Tetraoctyl titanate (TOT) ... 2-propanol solution, titanium content 8.5% by mass
(Other metal-containing components)
Alumina particles: Average particle size D50: 0.3 μm, specific surface area 12.5 m ² / g
Tricobalt tetraoxide particles ... Average particle size D50: 0.6 μm.

[Preparation of evaluation board]
Conductive pastes of Examples 1 to 11, Reference Example 1 and Comparative Examples 1 to 10 were prepared according to the composition of the inorganic components shown in Tables 1 to 4. As a method for preparing the paste, an organic vehicle in which 10% by mass of ethyl cellulose is dissolved in a mixed solvent of texanol / butylcarbitol acetate = 55/35 (mass ratio) and the inorganic components shown in Tables 1 to 4 are mixed. The paste was prepared. At that time, the solid content concentration of the inorganic component in the conductive paste was adjusted to 87% by mass. Then, using the prepared paste, electrodes were formed on an alumina substrate having a thickness of 3 inches × 3 inches × 0.635 mm by screen printing, and fired at 900 ° C. in the atmosphere to prepare an evaluation substrate.

[Initial judgment]
(Sulfide resistance test)
Atmospheric temperature 40 ° C., a relative humidity of 90%, _{H 2} S concentration was left 450 hours in an environment of a gas mixture 2.0ppm and NO ₂ concentration was adjusted to 4.0 ppm, performs sulfidation test, following criteria Judged by.

⊚: No sulfurization point is observed ○: Sulfidation point is slightly observed ×: Overall sulfurization.

(Plating resistance, initial adhesive strength)
After electroless plating (Ni / Pd / Au), the adhesion was evaluated at the 2 mm square pad pattern portion. A tin-plated annealed copper wire (peel wire) was soldered along the surface of the 2 mm square pad. At this time, if the electrode was peeled off just by lifting the copper wire, the plating resistance evaluation was ×.

An annealed copper wire bent vertically upward at a position located at the end of the pad was fixed to a tensile tester and pulled up until the pad was peeled off from the substrate. The highest load when the pad peeled from the substrate was recorded as the peel strength (2 mm pattern peel strength). The obtained peel strength was evaluated according to the following criteria. The peel strength of 3 kgf or more means that the peel strength per 1 mm of the pattern is 0.75 kgf or more, and the case where the electrode is peeled off only by lifting the copper wire is set to 0 kgf.

⊚: 3 kgf or more ○: 2 kgf or more and less than 3 kgf ×: less than 2 kgf.

(Specific resistance)
The specific resistance was calculated from the surface resistance and the film thickness in the four-probe method. For each of the conductive films obtained in Examples and Comparative Examples, 10 samples were measured, and the average value was calculated.

(Judgment method of initial judgment)
The results of the above evaluation test were judged and ranked according to the following criteria as an initial judgment.

Rank A: Sulfurization resistance and plating resistance are both ◎ (passed)
Rank B: One of sulfur resistance and plating resistance is ○, and neither is × (pass)
Rank C: There is a cross in sulfurization resistance and plating resistance (failure).

[Comprehensive judgment]
The following reliability evaluations were performed on the substrates that passed the initial judgment to make a comprehensive judgment.

(Constant temperature and humidity test)
In the constant temperature and humidity test, the adhesive strength (adhesive strength) of the fired film was measured after being left in a constant temperature and humidity bath at a temperature of 85 ° C. and a relative humidity of 85% RH for 1000 hours, and the determination was made according to the following criteria.

⊚: 2 kgf or more ○: 1.5 kgf or more and less than 2 kgf ×: less than 1.5 kgf.

(Heat cycle test)
The adhesive strength after 1000 cycles at −40 ° C./125 ° C. was measured and judged according to the following criteria.

⊚: 2 kgf or more ○: 1.5 kgf or more and less than 2 kgf ×: less than 1.5 kgf.

(Heat aging test)
The adhesive strength was measured after 1000 hours in an oven at 170 ° C., and the determination was made according to the following criteria.

⊚: 2 kgf or more ○: 1.5 kgf or more and less than 2 kgf ×: less than 1.5 kgf.

(Judgment method of comprehensive judgment)
The results of the above evaluation test were judged and ranked according to the following criteria as a comprehensive judgment.

Rank A: All reliability tests are ◎ (pass)
Rank B: Reliability test is ◎ and ○, or all ○ (pass)
Rank C: There is a cross in the reliability test, or rank C (failed) in the initial judgment.

Tables 1 to 4 show the evaluation results of the evaluation substrates obtained in Examples 1 to 11, Reference Example 1 and Comparative Examples 1 to 10.

The details of the ratios (mass%) shown in Tables 1 to 4 are as follows.

"Ratio of metal component (C)" means the ratio (mass%) of the metal component (C) in terms of metal element to the total amount of AgPd particles and spherical Ag particles (total amount of AgPd particles and spherical Ag particles 100 mass). The mass part of the metal element contained in the metal component (C) with respect to the part).

“Ratio of Ti component (C4)” means the ratio (mass%) of Ti component (C4) in terms of metal element to the total amount of AgPd particles and spherical Ag particles.

The "ratio of the Mn component (C1), Fe component (C2), and Cu component (C3)" is the Mn component (C1), Fe component (C2), and Cu component (C3) with respect to the total amount of AgPd particles and spherical Ag particles. It means the ratio (mass%) of the total amount in terms of metal elements (mass part of the total amount of metal elements contained in each metal component with respect to 100 parts by mass of the total amount of AgPd particles and spherical Ag particles).

"Ratio of Pd" means the ratio (mass%) of Pd element to the total amount of Ag element and Pd element contained in the composition.

“Ratio of glass particles (B)” means the ratio (mass%) of glass particles (B) to the total amount of AgPd particles and spherical Ag particles.

As is clear from the results in Tables 1 to 4, the substrates obtained in the examples have high plating resistance and sulfurization resistance, and are highly reliable regardless of changes in the usage environment, whereas the reference examples and the substrates The substrate obtained in the comparative example could not satisfy all of plating resistance, sulfurization resistance, and reliability.

Specifically, as is clear from the results in Table 1, in Comparative Example 3 containing no Ti component, the plating resistance (adhesion) was insufficient. Further, even in Reference Example 1 in which the Ti component and Ag particles coexist, the plating resistance (adhesion) was insufficient. As the Ti component, Example 1 using titanium dioxide particles was excellent in plating resistance (adhesion), and was judged as A in the reliability test. In addition, even in Examples 2 to 3 using tetraoctyl titanate, although it was inferior to the titanium dioxide particles, it was judged as B in the reliability test, which was a practical level. On the other hand, in Comparative Examples 1 and 2 in which alumina particles and tricobalt tetraoxide particles were used as other metal components instead of the Ti component, reliability and plating resistance (adhesion) were insufficient. Further, in Comparative Example 4 containing no Pd, there was no problem in plating resistance (adhesion), but there was a problem in sulfurization resistance. Further, even in Comparative Examples 5 to 7 containing only two types of Mn compound (C1), Fe compound (C2), and Cu compound (C3), the electrodes did not adhere at all, so the plating resistance was unacceptable.

The results of Example 1, which had the best balance of various characteristics, are shown not only in Table 1 but also in Tables 2 to 4 for comparison.

As is clear from the results in Table 2, in Examples 4 to 6 in which the ratio of the Ti component (C4) to the AgPd composite particle (A) was variable with respect to Example 1, the Ti component (C4) was found in Comparative Example 8. The ratio was 0.3 to 0.5% by mass, and the initial judgment and the comprehensive judgment were A judgments (passed). Even with a small proportion of 0.1% by mass and a large proportion of 0.8% by mass, the initial judgment was B judgment, which was a practically acceptable level. In the excess 0.9% by mass of Comparative Example 8, both the initial judgment and the comprehensive judgment were C judgments.

As is clear from the results in Table 3, in Example 8 in which the ratio of Pd was varied to 7.5% by mass with respect to Example 1 in which the ratio of Pd was 5% by mass, it was as good as in Example 1. The result was In Example 7 in which the proportion of Pd was as small as 1.0% by mass, the plating resistance (adhesion) was good, but the sulfurization resistance was lowered. In Comparative Example 9 (10% by mass) and Comparative Example 10 (12.5% by mass) in which the proportion of Pd was large, plating resistance could not be obtained (no adhesion at all).

As is clear from the results in Table 4, Examples 10 to 11 are examples in which the type of glass particles is changed with respect to Example 1, and Examples 10 using zinc-based glass particles and bismuth-based glass particles are used. In Example 11 using the above, the plating resistance and reliability were slightly lowered due to the lowered adhesion. In Example 9 in which the amount of glass particles was increased as compared with Example 1, the same results as in Example 1 were obtained.

The conductive composition of the present invention can be used for circuit boards, electronic components, thermal boards, LED package boards, semiconductor boards, thin film circuit boards, resistor boards, etc., and forms conductive parts such as electrodes in wiring circuit boards. It can be particularly effectively used as a composition for this purpose.

Claims (9)

A conductive composition containing a composite particle (A) of Ag and Pd, a glass particle (B) and a metal component (C), wherein the metal component (C) is an Mn component (C1) and an Fe component (C2). , Cu component (C3) and Ti component (C4), and the ratio of the Ti component is 0.05 to 0.85 parts by mass with respect to 100 parts by mass of the composite particle (A) in terms of Ti element. A conductive composition. The conductive composition according to claim 1, wherein the ratio of Pd to the total amount of Ag and Pd is 1 to 9% by mass. The conductive composition according to claim 1 or 2, wherein the glass particles (B) contain borosilicate glass particles. The conductive composition according to any one of claims 1 to 3, wherein the Ti component (C4) is an inorganic Ti compound. The conductive composition according to any one of claims 1 to 4, which does not contain Ag particles. The bonding step of adhering the conductive composition according to any one of claims 1 to 5 to the ceramic substrate, and the firing step of firing the conductive composition adhered to the ceramic substrate to form a conductive portion. Method of manufacturing a metallized substrate including. The production method according to claim 6, wherein the conductive composition is fired in air in the firing step. A metallized substrate obtained by the manufacturing method according to claim 6 or 7. The metallized substrate according to claim 8, wherein the ceramic substrate is an alumina substrate, an alumina-zirconia substrate, an aluminum nitride substrate, a silicon nitride substrate, or a silicon carbide substrate.