Method for manufacturing inkjet ink, ink sets, and electronic components

Abstract

Providing technology to reduce sheet attack properties using ceramic inkjet inks. [Solution] The inkjet ink disclosed herein is used in the manufacture of electronic components. The inkjet ink is non-aqueous and contains a first ceramic powder, a binder resin, and an organic solvent. The organic solvent contains dimethyl sulfoxide, an alkanediol, and a saturated monohydric alcohol. The Fedors SP value of the entire organic solvent is 13.5 (cal / cm²). 3 ) 1 / 2 More than 14.5(cal / cm 3 ) 1 / 2 The following applies:

Description

[Technical Field]

[0001] This disclosure relates to inkjet inks, ink sets, and methods for manufacturing electronic components. [Background technology]

[0002] Inkjet printing has long been used as a printing method for drawing images such as patterns and characters onto a printing surface. Because inkjet printing allows for high-precision image printing at low cost and on demand, and causes minimal damage to the printing surface, its application in various fields is being explored. In recent years, the use of inkjet printing in the manufacturing of electronic components, specifically for forming conductive circuit patterns (wiring, electrodes, etc.) and insulating layers that insulate these conductive circuit patterns, is being considered. The main objective is to achieve miniaturization and increased density of electronic components. For example, it is expected that the electrode layers and insulating layers in laminates contained within electronic components can be made thinner than those in laminates produced using screen printing.

[0003] For example, Japanese Patent Publication No. 2023-140758 discloses a conductive inkjet ink used in the manufacture of electronic components. This conductive inkjet ink contains at least an inorganic powder and an organic solvent for dispersing the inorganic powder. The organic solvent includes a first organic solvent, a second organic solvent, and a third organic solvent. Each organic solvent has a different viscosity and Hildebrand solubility parameter. In this conductive inkjet ink, the content of each organic solvent is set to satisfy a predetermined range when the total weight of the organic solvent is 100% by weight. The publication states that this configuration can suppress the occurrence of sheet attack and improve discharge performance.

[0004] For example, Japanese Patent Application Laid-Open No. 2008-34345 discloses a conductive oxide particle dispersion liquid used when forming a transparent conductive film such as various display devices including liquid crystals by a coating method. This dispersion liquid is a dispersion liquid in which conductive oxide particles (A) having an average particle diameter of 1 to 500 nm surface-modified with a halogen element are dispersed in an organic solvent (B) not containing a dispersant. The organic solvent (B) contains a cyclic ketone compound as a main component. The amount of water contained in the dispersion liquid is 1.5 parts by weight or less with respect to 100 parts by weight of the conductive oxide particles. The same publication describes that with such a configuration, the conductive oxide particles can be stably dispersed without using a dispersant.

[0005] For example, Japanese Patent No. 5398415 discloses an ink set including an ink composition and a maintenance liquid. The ink composition contains a pigment coated with a water-insoluble polymer obtained by copolymerizing a monomer mixture containing a styrene-based macromer, polymer particles, a water-soluble organic solvent, and water. The maintenance liquid is a liquid for removing deposits derived from the ink composition from the head nozzle surface. The maintenance liquid contains 50% by mass or more and 99% by mass or less of water and 1% by mass or more and 50% by mass or less of an organic solvent with respect to the total mass. 50% by mass or more of the organic solvent is a solvent having an SP value of 27.5 or less. The same publication describes that with such a configuration, while ensuring long-term ejection reliability, an image excellent in print quality with good image gloss, abrasion resistance, and offset resistance can be formed, and the image formation speed can be increased.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0007] Incidentally, some electronic components are multilayer products (e.g., multilayer ceramic capacitors (MLCCs)) that require high smoothness in the electrode layer and insulating layer. In such multilayer electronic components, ferroelectric ceramic materials such as barium titanate are used for the insulating layer, and metallic materials such as palladium or nickel are used for the electrode layer. In the manufacturing process of the electrode layer and insulating layer, first, a ceramic layer (e.g., insulating layer) is formed on a plastic film such as a PET film that has been treated to make the surface smooth, using a ceramic slurry by a doctor blade method, screen printing method, etc. On top of that, a metal layer (e.g., electrode layer) is formed using a metal slurry (paste), for example by a screen printing method. Next, the green sheets obtained by peeling all the printed material from the PET film are laminated, and then pressed and fired to form a multilayer electronic component. Here, in order to peel the above layers from the PET film, it is necessary to give each green sheet an appropriate strength. For this reason, there are limits to how much the thickness of the layers provided on the PET film can be reduced.

[0008] The inventors are investigating a method for forming laminated components by alternately inkjet printing the insulating layer pattern and electrode layer pattern of electronic components requiring high smoothness using ceramic inkjet ink mainly composed of ceramics such as barium titanate particles and conductive inkjet ink mainly composed of metals such as nickel particles. The objective is to thin both the electrode layer and the insulating layer, which has been difficult with the combination of green sheet, ceramic paste, and conductive paste, as miniaturization and capacity reduction of components are progressing in MLCC manufacturing. By smoothing both the electrode layer and the insulating layer, miniaturization that was not possible with conventional screen printing methods can be achieved. In addition, for example, since it becomes unnecessary to form each layer on a PET film, it becomes unnecessary to peel the layers from the PET film, thereby increasing productivity.

[0009] In lamination of an electrode layer and an insulating layer, for example, conductive inkjet ink is printed onto a ceramic green sheet, and then ceramic inkjet ink is printed on top of that. In this case, it is required that the conductive inkjet ink does not dissolve the ceramic green sheet (i.e., it has no sheet-attack properties towards the ceramic green sheet), and that the ceramic inkjet ink does not dissolve the printed film of the conductive inkjet ink (i.e., it has no sheet-attack properties towards the printed film of the conductive inkjet ink). Furthermore, depending on the shape of its pattern, the electrode layer may be adjacent to an insulating region formed by a printed film of ceramic inkjet ink, for example. In this case, the inkjet inks used to form both must not have mutual sheet-attack properties.

[0010] This invention has been made in view of these circumstances, and its purpose is to provide a technology for reducing the sheet attack properties of ceramic inkjet ink. [Means for solving the problem]

[0011] The inkjet ink disclosed herein is used in the manufacture of electronic components. The inkjet ink is non-aqueous and contains a first ceramic powder, a binder resin, and an organic solvent. The organic solvent contains dimethyl sulfoxide, an alkanediol, and a saturated monohydric alcohol. The Fedors SP value of the entire organic solvent is 13.5 (cal / cm³). 3 ) 1 / 2 More than 14.5(cal / cm 3 ) 1 / 2 The following configuration makes it possible to reduce the sheet-attack properties of inkjet ink against other printed films.

[0012] In other respects, an ink set is disclosed according to the technology disclosed herein. The ink set disclosed herein is used in the manufacture of electronic components. The ink set comprises a first ceramic inkjet ink, which is the inkjet ink described above, and a conductive inkjet ink. The conductive inkjet ink comprises a metal powder, a polyvinyl butyral resin containing less than 28 mol% hydroxyl groups, a dispersant, and an organic solvent. With this configuration, the occurrence of sheet attack by the ceramic inkjet ink on the printed film of the conductive inkjet ink can be suppressed.

[0013] In other respects, the technology disclosed herein discloses a method for manufacturing electronic components. This manufacturing method includes: providing a printed film of conductive ink on the surface of a substrate; laminating a printed film of a first ceramic ink, which is the inkjet ink, onto the printed film of conductive ink; and heat-treating the laminate of the substrate, the printed film of conductive ink, and the printed film of the first ceramic ink. The conductive inkjet ink comprises metal powder, a polyvinyl butyral resin containing less than 28 mol% hydroxyl groups, a dispersant, and an organic solvent. With this configuration, electronic components can be manufactured while suppressing the occurrence of sheet attack by the ceramic inkjet ink on the printed film of conductive inkjet ink. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a cross-sectional view of the laminate L. [Figure 2] Figure 2 is a cross-sectional view of the stirring and grinding machine 100. [Figure 3] Figure 3 is an overall view of the inkjet device 1. [Figure 4] Figure 4 is a cross-sectional view of the inkjet head 10. [Modes for carrying out the invention]

[0015] Embodiments of the technology disclosed herein will be described below. Matters other than those specifically mentioned herein but necessary for implementing the technology disclosed herein can be understood as design matters for those skilled in the art based on prior art in the relevant field. The technology disclosed herein can be implemented based on the content disclosed herein and common technical knowledge in the relevant field. In this specification, the notation "P~Q" indicating a numerical range includes the cases of "P or more and Q or less", "greater than P and less than Q", "greater than P and less than or equal to Q", and "P or more and less than Q".

[0016] <Laminated body L> Figure 1 is a cross-sectional view of the laminate L. Figure 1 shows the cross-sectional structure of each layer included in the laminate L. As shown in Figure 1, the laminate L comprises a base material S, a metal layer M, a first ceramic layer C1, and a second ceramic layer C2. From the bottom to the top of Figure 1, the base material S, the metal layer M, and the first ceramic layer C1 are laminated. In this embodiment, the metal layer M and the second ceramic layer C2 are sandwiched between the base material S and the first ceramic layer C1. The second ceramic layer C2 and the metal layer M are adjacent to each other. In this embodiment, the laminate L is an unfired body. Each layer will be described below.

[0017] <Base material S> The base material S is, for example, a base material used in this type of electronic component. The base material S may be, for example, a base material made by solidifying ceramic powder with a binder resin.

[0018] <First ceramic layer C1> The first ceramic layer C1 is, for example, an insulating layer that insulates the lower metal layer M from the upper metal layer M (not shown). The first ceramic layer C1 is a printed film of the first ceramic inkjet ink (hereinafter also simply referred to as "first ceramic ink"), which is the inkjet ink disclosed herein. In this specification, "printed film" refers to a film-like material (dried film) obtained by applying ink to a substrate (substrate S in Figure 1) and drying it. The printed film here is an unfired body.

[0019] The first ceramic ink may include, for example, (A) a first ceramic powder, (B) a binder resin, and (C) an organic solvent. In the first ceramic ink, for example, the first ceramic powder is dispersed in an organic vehicle component (a mixture of the binder resin and the organic solvent). The components contained in the first ceramic ink are described below.

[0020] The first ceramic ink is non-aqueous. In this specification, "non-aqueous" means substantially free of water, and refers to a water content of 1% by mass or less, 0.5% by mass or less, or 0.1% by mass or less relative to the entire first ceramic ink.

[0021] (A) First ceramic powder The first ceramic powder is a material that constitutes the first ceramic layer C1 on the substrate S. The first ceramic powder is also a material that constitutes the fired body of the printed film (hereinafter also referred to as the "fired film") (for example, an insulating layer) obtained by firing the printed film. In the first ceramic ink, the first ceramic powder may contain the first ceramic as its main component. Here, in this specification, "R contains S as its main component" means that when the total R (for example, the entire first ceramic powder) is considered to be 100% by mass, the content of S (for example, the first ceramic) is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more (the closer to 100% by mass, the better).

[0022] The first ceramic powder is composed of, for example, first ceramic particles. The first ceramic particles may contain not only the first ceramic that constitutes the particles, but also unavoidable impurities that may be mixed in during the production process of the first ceramic particles. The first ceramic powder may consist of one type of ceramic powder, or it may consist of two or more types of ceramic powder.

[0023] The type of the first ceramic powder does not need to be particularly limited as long as it is appropriately set according to the function imparted to the fired film formed using the first ceramic ink. Examples of the ceramic constituting the first ceramic powder include metal oxides having a perovskite structure represented by ABO3 such as barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, zirconium titanate, zinc titanate, magnesium barium niobate, calcium zirconate, barium zirconium titanate, etc.; titanium dioxide (rutile), titanium pentoxide, hafnium oxide, zirconium oxide, aluminum oxide (alumina), forsterite, niobium oxide, barium neodymium titanate, rare earth element oxides, etc.; BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (hereinafter referred to as BZCYY); may be mentioned. In the formula of BZCYY, δ is the oxygen deficiency amount and satisfies 0 ≦ δ ≦ 1.

[0024] The particle size of the first ceramic powder in the first ceramic ink is one of the factors that affect, for example, the ejection performance, the stability over time, and the smoothness of the printed film. For example, from the viewpoint of suppressing a decrease in the ejection performance of an inkjet device due to clogging of the ejection port with the first ceramic powder, the average particle size of the first ceramic powder is, for example, 500 nm or less, preferably 450 nm or less, more preferably 400 nm or less, and even more preferably 350 nm or less. Also, from the viewpoint of improving the smoothness of the printed film, the average particle size of the first ceramic powder is, for example, 320 nm or less, more preferably 300 nm or less, even more preferably 250 nm or less, and particularly preferably 200 nm or less. On the other hand, from the viewpoint of suppressing aggregation of particles and suppressing a decrease in the stability over time of the first ceramic ink, the average particle size of the first ceramic powder is, for example, 5 nm or more, preferably 10 nm or more, and more preferably 20 nm or more. In this specification, "average particle size" refers to the average particle size based on the dynamic light scattering (DLS) method. The average particle size based on this DLS method is measured in accordance with JIS Z 8828:2013.

[0025] The volume ratio of the first ceramic powder in the first ceramic ink is not particularly limited and can be set appropriately according to the printing purpose. For example, as the volume ratio of the first ceramic powder in the first ceramic ink increases, a printing layer of a suitable thickness can be formed with fewer printing cycles. From this viewpoint, when the total volume of the first ceramic ink is 100% by volume, the volume ratio of the first ceramic powder is generally 0.1% by volume or more, preferably 0.5% by volume or more, and more preferably 1% by volume or more. On the other hand, as the volume ratio of the first ceramic powder decreases, there is a tendency for the long-term stability and ejection properties to improve. From this viewpoint, when the total volume of the first ceramic ink is 100% by volume, the content of the first ceramic powder is generally 20% by volume or less, preferably 15% by volume or less, and more preferably 10% by volume or less.

[0026] The content of the first ceramic powder in the first ceramic ink can be appropriately set, for example, according to the desired thickness of the printed film. Here, when the entire first ceramic ink is considered to be 100% by mass, the content of the first ceramic powder is generally 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more. On the other hand, when the entire first ceramic ink is considered to be 100% by mass, the content of the first ceramic powder is, for example, 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. When the entire first ceramic ink is considered to be 100% by mass, the content of the first ceramic powder is generally 3% by mass to 30% by mass, and preferably 5% by mass to 25% by mass.

[0027] (B) Binder resin The binder resin is the component that fixes the first ceramic powder onto the metal layer M and the second ceramic layer C2 after inkjet printing. The first ceramic ink, which is inkjet printed onto the metal layer M and the second ceramic layer C2, is then subjected to a firing treatment, for example, after being heated and dried on a substrate S. Therefore, it is preferable that the binder resin completely disappears (burns out) during the firing treatment. As the binder resin, polyvinyl acetal resin is preferably used, for example.

[0028] The first ceramic ink preferably contains a polyvinyl acetal resin as a binder resin. Polyvinyl acetal resin is, for example, a resin produced by acetalizing a polyvinyl alcohol resin with an aldehyde. In addition to the function of fixing the first ceramic powder to the metal layer M and the second ceramic layer C2 as described above, the polyvinyl acetal resin has the function of dispersing in an organic solvent and assisting in the effect of suppressing the precipitation of the first ceramic powder by a dispersant. Furthermore, with polyvinyl acetal resin, for example, a configuration suitable for suppressing the occurrence of sheet attack can be realized by adjusting the content of hydroxyl groups contained in the resin. For this reason, polyvinyl acetal resin is suitable as a binder resin for the first ceramic ink. Suitable examples of polyvinyl acetal resin include, for example, polyvinyl butyral resin and polyvinyl formal resin.

[0029] The weight-average molecular weight of the binder resin can be set appropriately, as long as it does not hinder the effects of the technology disclosed herein. For example, from the viewpoint of appropriately exhibiting the precipitation suppression effect of the first ceramic powder, the weight-average molecular weight of the binder resin can be, for example, 0.5 × 10⁻⁶. 4 It is good if it is greater than or equal to 1.0 × 10 4 The above is preferable, 1.5 × 10 4 The above is more preferable. On the other hand, from the viewpoint of maintaining the viscosity of the first ceramic ink in an appropriate state and suppressing a decrease in dispensing performance, the weight-average molecular weight of the binder resin is, for example, 10 × 10 4 It is often the case that it is less than 7.5 × 10 4 The following is preferable: 5.0 × 10 4 The following is more preferable: 4.5 × 10 4 The following is even more preferable: 2.5 × 10 4The following is particularly preferred. As the weight-average molecular weight of the binder resin, for example, the weight-based average molecular weight obtained by measuring by gel permeation chromatography (GPC) and converting it using a standard polystyrene calibration curve is adopted. For such measurement, for example, a GPC instrument (HLC-8320) manufactured by Tosoh Corporation may be used. Alternatively, a nominal value from the manufacturer of the resin binder or a value calculated based on the chemical formula may be adopted.

[0030] The glass transition temperature of the binder resin can be set as appropriate, as long as it does not hinder the effects of the techniques disclosed herein. For example, from the viewpoint of forming a dry film with excellent adhesion, the glass transition temperature of the binder resin is preferably 40°C or higher, more preferably 50°C or higher, and even more preferably 60°C or higher. Such a glass transition temperature is, for example, 100°C or lower, preferably 95°C or lower, and more preferably 90°C or lower. In this specification, "glass transition temperature" refers to the glass transition temperature (Tg) based on differential scanning calorimetry (DSC). Alternatively, a nominal value from a manufacturer or the like may be used.

[0031] From the viewpoint of reducing sheet attack on the metal layer M and the second ceramic layer C2, it is preferable to use a polyvinyl acetal resin (e.g., polyvinyl butyral resin) which has higher polarity than the binder resin contained in the inkjet ink used to form these layers as the binder resin. In the polyvinyl acetal resin contained in the first ceramic ink, the hydroxyl group content is generally 28 mol% or more. From the viewpoint of suppressing sheet attack on the metal layer M and the second ceramic layer C2, the hydroxyl group content is, for example, 29 mol% or more, preferably 30 mol% or more, and more preferably 31 mol% or more. Although not particularly limited, from the viewpoint of improving solubility in the organic solvent described later, the hydroxyl group content is, for example, 40 mol% or less, preferably 38 mol% or less, more preferably 36 mol% or less, and even more preferably 34 mol% or less.

[0032] The hydroxyl group content in the binder resin is, in this context, the hydroxyl group content in the polyvinyl acetal resin, with the hydroxyl group content of the polyvinyl alcohol resin before acetalization with aldehydes being set to 100 mol%. For such hydroxyl group content, for example, the nominal value from the manufacturer may be adopted. Alternatively, the measured value obtained using the measurement method described in JIS K0070:1992 "Test methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiables of chemical products" may be adopted.

[0033] The volume percentage of the binder resin in the first ceramic ink can be set appropriately, as long as it does not hinder the effects of the technology disclosed herein. For example, when the entire first ceramic ink is 100 volume%, the volume percentage of the binder resin is generally 0.3 volume% to 3 volume%, and preferably 0.5 volume% to 1.5 volume%.

[0034] (C) Organic solvents The organic solvent can disperse the first ceramic powder and impart to the first ceramic ink fluidity and other properties suitable for inkjet printing. The first ceramic ink is required, for example, not to cause sheet attack against the metal layer M and the second ceramic layer C2. From this viewpoint, the inventors considered using dimethyl sulfoxide (DMSO) as the organic solvent contained in the first ceramic ink, taking into account the resin binder used in the metal layer M and the second ceramic layer C2. However, it was found that DMSO is not suitable for properly ejecting ink from the inkjet head due to its high surface tension. Therefore, the inventors investigated other components of the organic solvent to be used in combination with DMSO, which have a molecular structure that can reduce the surface tension of DMSO and reduce sheet attack against the metal layer M and the second ceramic layer C2. As a result of diligent research, the inventors arrived at a composition of an organic solvent that contains DMSO, can suppress the occurrence of sheet attack against the metal layer M and the second ceramic layer C2, and has viscosity and surface tension suitable for inkjet printing.

[0035] In the first ceramic ink, the organic solvents include DMSO, alkanediol, and saturated monohydric alcohol. The Fedors SP value of the entire organic solvent is 13.5 (cal / cm³). 3 ) 1 / 2 ~14.5 (cal / cm 3 ) 1 / 2 Therefore, the Fedors SP value for the entire organic solvent is, in this context, the weighted average SP value of the organic solvent. The "weighted average SP value of the organic solvent" here refers to the sum of the products of the SP values ​​of each component of the organic solvent contained in the ink and the composition ratio of each component of the organic solvent (in this case, the volume ratio of each component).

[0036] In this specification, "SP value" refers to the solubility parameter (SP) calculated using the method (Fedors method) described in RFFedors, Polymer Engineering Science, 14, p147 (1974). The SP value is unique to each compound. The SI unit of the SP value is (J / cm²). 3 ) 1 / 2 or (MPa) 1 / 2 However, in this specification, the conventionally used (cal / cm 3 ) 1 / 2 The SP value is used. The unit of the SP value is given by the following formula: 1 (cal / cm 3 ) 1 / 2 ≈2.05 (J / cm) 3 ) 1 / 2 ≈2.05 (MPa) 1 / 2 It can be converted using semicolons.

[0037] In this specification, "alkanediol" refers to a group of compounds in which each of two hydrogen atoms of a chain-type saturated hydrocarbon is substituted with a hydroxyl group. In the first ceramic ink, the alkanediol is not particularly limited, but for example, an alkanediol having the following surface tension, Fedors SP value, and boiling point can be preferably used. The surface tension of the alkanediol is, for example, 45 mN / m to 50 mN / m, preferably 46 mN / m to 49 mN / m, and more preferably 47.5 mN / m to 48.5 mN / m. The Fedors SP value of the alkanediol is 15 (cal / cm²). 3 ) 1 / 2 ~18 (cal / cm) 3 ) 1 / 2 This is preferable. The boiling point of the alkanediol is preferably 180°C to 220°C under atmospheric pressure, taking into account the volatility of the organic solvent during heating and drying of the ink. The organic solvent may contain one type of alkanediol or two or more types of alkanediol. The surface tension, SP value, and boiling point mentioned above are the surface tension, SP value, and boiling point of each alkanediol contained in the organic solvent.

[0038] The surface tension of the entire organic solvent and its constituent components can be measured, for example, using a commercially available static surface tension meter. Alternatively, the manufacturer's nominal values ​​may be used. The SP value of the organic solvent is, for example, the value calculated as described below. The boiling points of the constituent components of the organic solvent should preferably be the manufacturer's nominal values.

[0039] While not particularly limited, the alkanediols should preferably be those with 6 or fewer carbon atoms, 5 or fewer carbon atoms, 4 or fewer carbon atoms, or 3 or fewer carbon atoms, and possess the physical properties described above.

[0040] In this specification, "saturated monohydric alcohol" refers to a group of compounds in which one hydrogen atom of a chain-type saturated hydrocarbon is substituted with a hydroxyl group. While not particularly limited, saturated monohydric alcohols having the following surface tension, Fedors SP value, and boiling point can be preferably used in the first ceramic ink. The surface tension of the saturated monohydric alcohol is, for example, 24 mN / m to 28 mN / m, and preferably 25 mN / m to 27 mN / m. The Fedors SP value of the saturated monohydric alcohol is 9 (cal / cm²). 3 ) 1 / 2 ~12 (cal / cm) 3 ) 1 / 2 This is preferable. The boiling point of the saturated monohydric alcohol is preferably 130°C to 180°C under atmospheric pressure conditions, taking into account the volatility of the organic solvent during the heating and drying of the first ceramic ink. The organic solvent may contain one saturated monohydric alcohol or two or more saturated monohydric alcohols. The surface tension, SP value, and boiling point mentioned above are the surface tension, SP value, and boiling point of each saturated monohydric alcohol contained in the organic solvent.

[0041] While not particularly limited, saturated monohydric alcohols are preferably saturated monohydric alcohols with 7 or fewer carbon atoms, 6 or fewer carbon atoms, 5 or fewer carbon atoms, or 4 or more carbon atoms, that possess the physical properties described above.

[0042] The volume percentages of each component when the total of DMSO, alkanediol, and saturated monohydric alcohol is 100% by volume are not particularly limited, as long as the SP value of the entire organic solvent is within the range described above and the effects of the technology disclosed herein are realized. For example, in order to prevent the viscosity of the first ceramic ink from becoming too high, the volume percentage of DMSO when the total of DMSO, alkanediol, and saturated monohydric alcohol is 100% by volume is preferably 10% by volume or more, and more preferably 20% by volume or more. For example, in order to prevent the surface tension of the first ceramic ink from becoming too high, the volume percentage of DMSO when the total of DMSO, alkanediol, and saturated monohydric alcohol is 100% by volume is preferably 70% by volume or less, and more preferably 60% by volume or less.

[0043] Insofar as the effects of the technology disclosed herein are realized, the organic solvent may contain other solvent components other than DMSO, the alkanediol described above, and the saturated monohydric alcohol described above. From the viewpoint of better realizing the effects of the technology disclosed herein, the total volume ratio of DMSO, the alkanediol described above, and the saturated monohydric alcohol described above to the whole organic solvent is generally 70% by volume or more, for example 80% by volume or more, preferably 85% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, particularly preferably 98% by volume or more, and the closer to 100% by volume, the better.

[0044] While not particularly limited, for example, from the viewpoint of improving the ejection performance of the first ceramic ink, when the entire first ceramic ink is considered to be 100% by volume, the volume percentage of the organic solvent is, for example, 80% by volume or more, preferably 85% by volume or more, and more preferably 90% by volume or more.

[0045] (D) Other ingredients The first ceramic ink may further contain known additives used in inkjet inks, to the extent that they do not impair the effects of the technology disclosed herein. The type of such additives, the amount added, etc., can be appropriately changed based on conventionally known common sense, and do not characterize the technology disclosed herein. Therefore, a detailed explanation is omitted here (the same applies to the conductive inkjet ink and the second ceramic inkjet ink described later).

[0046] While not particularly limited, it is preferable that the first ceramic ink is substantially free of dispersants. This prevents organic components (e.g., a mixture of resin binder and additives added to the first ceramic ink as needed) from interacting with other inks (e.g., conductive ink used to form the metal layer M, second ceramic ink used to form the second ceramic layer C2, etc.) in the printed film of the first ceramic ink, causing them to become liquid and flow, and consequently achieving a shape-retention effect on the printed film.

[0047] Next, the procedure for preparing (manufacturing) the first ceramic ink will be described. The first ceramic ink is prepared by mixing the above-mentioned components and then crushing and dispersing the first ceramic powder. Figure 2 is a cross-sectional view of the stirring and grinding machine 100. The following description is merely an example of a means for preparing the first ceramic ink and is not intended to limit the technology disclosed herein.

[0048] In manufacturing the first ceramic ink, first, a slurry (including paste and suspension), which is a precursor to the first ceramic ink, is prepared by weighing and mixing the above-mentioned components. Then, the first ceramic ink is prepared by stirring the slurry and crushing the first ceramic powder using a stirring and grinding machine 100 as shown in Figure 2. For example, after adding crushing beads (e.g., zirconia beads with an average particle size of 10 μm to 150 μm) to the slurry, the slurry is supplied from the supply port 110 into the stirring container 120. Inside the stirring container 120 is a shaft 134 having multiple stirring blades 132. One end of the shaft 134 is attached to a motor (not shown), and by operating the motor and rotating the shaft 134, the slurry is stirred while being sent downstream in the liquid supply direction D by the multiple stirring blades 132. During this stirring, the first ceramic powder is crushed by the crushing beads, and the finely granulated first ceramic powder is dispersed in the slurry.

[0049] The slurry, which has been sent downstream in the liquid delivery direction D, then passes through the filter 140. As a result, the first ceramic powder, crushing beads, etc. that have not been atomized are collected in the filter 140, and the first ceramic ink, in which the first ceramic powder is sufficiently dispersed, is discharged from the outlet 150. In this process, the average particle size of the first ceramic powder can be adjusted to a desired range by appropriately adjusting the pore size of the filter 140, the average particle size of the crushing beads, etc.

[0050] <Metal layer M> The metal layer M is, for example, a wiring or electrode layer. In this embodiment, the metal layer M is a printed film of conductive inkjet ink (hereinafter also simply referred to as "conductive ink"). The conductive ink may include, for example, metal powder, a polyvinyl butyral resin containing less than 28 mol% hydroxyl groups, a dispersant, and an organic solvent.

[0051] The metal powder is, for example, a component that imparts conductivity to the metal layer M. Various metal powders used in this type of metal layer M can be used without particular limitation. The metal powder is composed of, for example, metal particles. The metal particles may contain not only the metal constituting them, but also unavoidable impurities that may be mixed in during the generation process of the metal particles. The metal powder may consist of one type of metal powder, or two or more types of metal powder. Examples of metals constituting the metal powder include elemental metals such as nickel (Ni), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), copper (Cu), ruthenium (Ru), rhodium (Rh), osmium (Os), iridium (Ir), aluminum (Al), and tungsten (W); and alloys containing these metals. Among these, from the viewpoint of chemical stability and safety, elemental nickel (Ni), nickel alloys such as copper-nickel alloys and nickel-chromium alloys are preferably used as the metal.

[0052] The average particle size of the metal powder in the conductive ink, the volume percentage of the metal powder in the conductive ink, and the content of the metal powder in the conductive ink are not particularly limited and may be appropriately set within a range similar to that of the average particle size, volume percentage in the first ceramic ink, and content in the first ceramic ink mentioned above for the first ceramic powder contained in the first ceramic ink.

[0053] The polyvinyl butyral resin contained in the conductive ink, as described above, functions as a binder resin. Therefore, the polyvinyl butyral resin has the function of fixing metal powder onto the substrate S after inkjet printing of the conductive ink onto the substrate S. Preferably, the polyvinyl butyral resin is thermally decomposed and burned away by, for example, a firing process. In the polyvinyl butyral resin, the hydroxyl group content is less than 28 mol%, preferably 25 mol% or less, more preferably 23 mol% or less, even more preferably 22 mol% or less, or may be 21 mol% or more, from the viewpoint of avoiding sheet attack from the first ceramic ink, solubility in organic solvents, etc.

[0054] The weight-average molecular weight, glass transition temperature, and volume percentage in the conductive ink of the polyvinyl butyral resin are not particularly limited and should be set appropriately within a range similar to that of the binder resin contained in the first ceramic ink, as previously mentioned.

[0055] A dispersant is a component that, for example, uniformly disperses metal particles in a conductive ink and suppresses aggregation and sedimentation of the metal particles. The conductive ink preferably contains a cationic dispersant. A cationic dispersant is, for example, a dispersant having a cationic functional group. Examples of cationic dispersants include amine-based dispersants, imidazoline-based dispersants, and quaternary ammonium-based dispersants. A single cationic dispersant may be used, or two or more may be used in combination. While not particularly limited, from the viewpoint of enhancing the dispersion effect of the cationic dispersant on metal particles, the dispersant may, if necessary, also contain a nonionic dispersant. The volume percentage of the dispersant in the conductive ink is not particularly limited, but is generally 0.5% to 5% and preferably 1% to 3% when the total conductive ink volume is 100%.

[0056] Organic solvents are components that, for example, disperse metal powders and impart fluidity to conductive inks suitable for inkjet printing. While not particularly limited, organic solvents generally have a boiling point of 140°C to 260°C, a viscosity of 0.5 mPa·s to 20 mPa·s, and a surface tension of 20 mN / m to 40 mN / m. Suitable examples of such organic solvents include glycol acetates and aliphatic monoalcohols. Examples of glycol acetates include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, butyl glycol acetate, butyl diglycol acetate (BDGAC), and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate. Examples of aliphatic monoalcohols include linear or branched aliphatic alcohols such as methanol, ethanol, propanol, isopropanol, butanol, n-amyl alcohol, hexanol, heptanol, n-octanol, 2-ethylhexanol, isooctanool, nonanol, decanol, isoundecanol, lauryl alcohol, cetyl alcohol, and stearyl alcohol. Mixed solvents of these organic solvents may also be used. Although not particularly limited, for example, from the viewpoint of improving the discharge performance of conductive ink, when the total conductive ink is considered to be 100% by volume, the volume percentage of the organic solvent is, for example, 80% by volume or more, preferably 85% by volume or more, and more preferably 90% by volume or more.

[0057] <Second ceramic layer C2> The second ceramic layer C2 constitutes, for example, an insulating region between the metal layers M. In this embodiment, the second ceramic layer C2 is a printed film of the second ceramic inkjet ink (hereinafter also simply referred to as "second ceramic ink"). The second ceramic ink may include, for example, the second ceramic powder, a thermoplastic resin, a dispersant, and an organic solvent.

[0058] The second ceramic powder is, for example, a component that imparts insulating properties to the second ceramic layer C2. The second ceramic powder is composed of, for example, second ceramic particles. The second ceramic particles may contain not only the ceramics that make up the second ceramic particles, but also unavoidable impurities that may be mixed in during the production process of the second ceramic particles. The second ceramic powder may consist of one type of ceramic powder, or it may consist of two or more types of ceramic powders. As the second ceramic powder, for example, the various ceramic powders mentioned above can be used without particular limitation. The type of second ceramic powder may be the same as or different from the type of first ceramic powder.

[0059] The average particle size of the second ceramic powder in the second ceramic ink, the volume ratio of the second ceramic powder in the second ceramic ink, and the content of the second ceramic powder in the second ceramic ink are not particularly limited and may be appropriately set within a range similar to that of the average particle size, volume ratio in the first ceramic ink, and content in the first ceramic ink mentioned above for the first ceramic powder contained in the first ceramic ink.

[0060] The thermoplastic resin contained in the second ceramic ink functions as a binder resin. Therefore, the thermoplastic resin has the function of fixing the second ceramic powder onto the substrate S after inkjet printing of the second ceramic ink onto the substrate S. Preferably, the thermoplastic resin is easily soluble in an organic solvent (described later) and easily burned away by thermal decomposition during a firing process. From this viewpoint, it is preferable that the thermoplastic resin has a basic skeleton composed of oxygen (O), carbon (C), and hydrogen (H).

[0061] As thermoplastic resins, for example, acrylic resins (including methacrylic resins) such as polymethyl methacrylate resin, polyethyl methacrylate resin, and polybutyl acrylate resin; polystyrene resins such as polystyrene and acrylonitrile-butadiene-styrene copolymer (ABS resin); polyolefin resins such as polyethylene, polypropylene, and cyclic olefins; polyvinyl acetate resin; polycarbonate resin; polyurethane resin; etc. are preferably used. Among these, acrylic resins (burn-out temperature: 250°C), polystyrene resins (burn-out temperature: 410°C), and polypropylene resins (burn-out temperature: 445°C) are more preferably used. Furthermore, acrylic resins with lower burn-out temperatures are preferably used.

[0062] The weight-average molecular weight of the thermoplastic resin should be set appropriately within a range similar to that of the binder resin contained in the first ceramic ink, for example, 2.0 × 10⁻⁶. 4 ~7.0×10 4 This is preferable. The glass transition temperature of the thermoplastic resin should be set appropriately within a range similar to that of the binder resin contained in the first ceramic ink, but 45°C to 80°C is preferred. The volume ratio of the thermoplastic resin in the second ceramic ink is not particularly limited and should be set appropriately within a range similar to that of the binder resin contained in the first ceramic ink, as described above.

[0063] The dispersant is, for example, a component that uniformly disperses the second ceramic particles in the second ceramic ink and suppresses aggregation and sedimentation of the second ceramic particles. The second ceramic ink preferably contains an anionic dispersant. The anionic dispersant is, for example, a dispersant having an anionic functional group. Examples of anionic dispersants include carboxylic acid-based dispersants, phosphoric acid-based dispersants, sulfonic acid-based dispersants, etc. One type of anionic dispersant may be used alone, or two or more types may be used in combination. The volume percentage of the dispersant in the second ceramic ink is not particularly limited, but is generally 0.5% to 5% by volume, and preferably 1% to 3% by volume, when the entire second ceramic ink is considered as 100% by volume.

[0064] The organic solvent is, for example, a component that disperses the second ceramic powder and imparts fluidity to the second ceramic ink suitable for inkjet printing. While not particularly limited, the organic solvent preferably has a boiling point of approximately 80°C to 260°C, a viscosity of 0.5 mPa·s to 20 mPa·s, and a surface tension of 20 mN / m to 40 mN / m. While not particularly limited, for example, from the viewpoint of improving the ejection performance of the second ceramic ink, when the total volume of the second ceramic ink is considered to be 100% by volume, the volume percentage of the organic solvent is, for example, 80% by volume or more, preferably 85% by volume or more, and more preferably 90% by volume or more.

[0065] The organic solvent here includes a first organic solvent and a second organic solvent. The first organic solvent is preferably an organic solvent that dissolves the thermoplastic resin described above but does not dissolve the binder resin contained in the green sheet, which is the base material S, or the polyvinyl butyral resin contained in the conductive ink. The first organic solvent is preferably an organic solvent that is less volatile than the first organic solvent and is preferably a saturated hydrocarbon with a vapor pressure of 4 Pa ​​or less at 20°C. The second organic solvent is preferably a linear alkane with 20 or fewer carbon atoms (preferably 10 to 16 carbon atoms), and tetradecane is preferred.

[0066] While not particularly limited, from the viewpoint of improving the solubility of the thermoplastic resin in the second ceramic ink and reducing the sheet attack on the substrate S and the metal layer M formed by the second ceramic ink, the volume ratio of the first organic solvent to the sum of the volumes of the first and second organic solvents in the ink is preferably 70% to 95% by volume. From the viewpoint of properly dispersing the second ceramic ink in the second ceramic ink and improving the smoothness of the printed film (here, the second ceramic layer C2), the value obtained by dividing the volume ratio Vs2 of the second organic solvent to the entire second ceramic ink by the volume ratio Vp of the ceramic powder to the entire ink (Vs2 / Vp) is preferably 1.5 to 3.

[0067] <Ink Set> The technology disclosed herein provides an ink set used in the manufacture of electronic components. The ink set comprises a first ceramic ink and a conductive ink. As described above, the first ceramic ink has reduced sheet attack properties on the metal layer M. Therefore, by using the ink set, the first ceramic layer C1, which is a printed film of the first ceramic ink, can be laminated without sheet attack on the metal layer M, which is a printed film of the conductive ink.

[0068] The ink set may further include a second ceramic ink. As described above, the first ceramic ink has reduced sheet attack properties on the second ceramic layer. Therefore, by using the ink set, the first ceramic layer C1 can be laminated without sheet attacking not only the metal layer M, which is the printed film of the conductive ink, but also the second ceramic layer C2, which is the printed film of the second ceramic ink.

[0069] <Applications of inkjet ink> The first ceramic ink, the conductive ink, the second ceramic ink, and the ink set are all used in the manufacture of electronic components. In this specification, "used in electronic components" includes not only the method of directly printing each ink onto the surface of an inorganic substrate, but also the method of indirectly adhering each ink to the surface of an inorganic substrate via an intermediate material such as transfer paper.

[0070] <Manufacturing methods for electronic components> A method for manufacturing an electronic component using the ink disclosed herein includes, for example, providing a printed film of conductive ink on the surface of a substrate; laminating a printed film of first ceramic ink onto the printed film of conductive ink; and subjecting the laminate of the substrate, the printed film of conductive ink, and the printed film of first ceramic ink to heat treatment. In this embodiment, the method for manufacturing an electronic component includes a first printing step, a first drying step, a second printing step, a second drying step, a third printing step, a third drying step, and a firing step. Each step will be described below with reference to Figures 1, 3, and 4. Figure 3 is an overall view of the inkjet device 1. Figure 4 is a cross-sectional view of the inkjet head 10.

[0071] The first printing step is, for example, the step of printing conductive ink onto the surface of a substrate S. In this embodiment, the apparatus shown in Figures 3 and 4 is used in this step. The inkjet ink printing procedure will be explained in the third printing step, which prints the inkjet ink (first ceramic ink) disclosed herein. The first drying step is, for example, the step of performing a drying treatment in which the substrate S on which the conductive ink has been printed is heated to a predetermined temperature. This removes the organic solvent from the conductive ink and forms a printed film (dried film) (metal layer M in Figure 1) on the substrate S. The heating temperature in the drying treatment can be set to a temperature (for example, 50°C to 150°C) that removes the organic solvent and does not cause sintering of the metal powder.

[0072] The second printing step is, for example, the step of printing a second ceramic ink onto the surface of the substrate S. Here, the second ceramic ink is printed on the substrate S in areas where the metal layer M formed through the first printing step and the first drying step does not exist. In this embodiment, the apparatus shown in Figures 3 and 4 is used in this step. The second drying step is, for example, the step of performing a drying treatment in which the substrate S on which the second ceramic ink has been printed is heated to a predetermined temperature. This removes the organic solvent from the second ceramic ink and forms a printed film (dried film) (second ceramic layer C2 in Figure 1) on the substrate S. The heating temperature in the drying treatment can be set to a temperature at which the organic solvent is removed and sintering of the second ceramic powder does not occur (for example, 50°C to 150°C).

[0073] The third printing step is, for example, the step of printing the first ceramic ink onto the surface of a metal layer M and a second ceramic layer C2 provided on a substrate S. In this embodiment, the apparatus shown in Figures 3 and 4 is used in this step. The first ceramic ink is printed onto the surface of the inorganic substrate W to be printed by an inkjet device 1 as shown in Figure 3. In this embodiment, the inorganic substrate W to be printed is a laminate of a metal layer M, a second ceramic layer C2, and a substrate S (see Figure 1). As shown in Figure 3, the inkjet device 1 includes an inkjet head 10 that stores the first ceramic ink. The inkjet head 10 is housed inside a printing cartridge 40. The printing cartridge 40 is inserted through a guide shaft 20 and is configured to reciprocate along the axial direction X of the guide shaft 20. Although not shown, the inkjet device 1 also includes a moving means for moving the guide shaft 20 in the vertical direction Y. This allows the inkjet device 1 to eject the first ceramic ink to a desired position on the inorganic substrate W.

[0074] For example, a piezo-type inkjet head like the one shown in Figure 4 may be used for the inkjet head 10. The piezo-type inkjet head 10 is provided with a storage section 13 for storing first ceramic ink inside a case 12, and the storage section 13 is in communication with the ejection section 16 via a liquid delivery path 15. The ejection section 16 is provided with an ejection port 17 that is open to the outside of the case 12, and a piezo element 18 is positioned opposite the ejection port 17. In the inkjet head 10, the first ceramic ink inside the ejection section 16 is ejected from the ejection port 17 toward the inorganic substrate W (see Figure 3) by vibrating the piezo element 18.

[0075] The third drying step involves a drying process in which the inorganic substrate W (here, the substrate S on which the first ceramic ink is printed (see Figure 1)) is heated to a predetermined temperature. This removes the organic solvent from the first ceramic ink, forming a printed film (dried film) (first ceramic layer C1 in Figure 1) on the surface of the metal layer M and the second ceramic layer C2. In this way, the laminate L shown in Figure 1 is obtained. The first ceramic ink is non-aqueous and contains DMSO, an alkanediol, and a saturated monohydric alcohol as organic solvents. The Fedors SP value of the entire organic solvent is 13.5 (cal / cm²). 3 ) 1 / 2 ~14.5 (cal / cm 3 ) 1 / 2 This reduces the sheet attack on the metal layer M and the second ceramic layer C2. Furthermore, in the first ceramic ink, the surface tension of DMSO is relaxed, achieving a surface tension and viscosity suitable for ejection from the inkjet head. The heating temperature in the drying process can be set to a temperature (for example, 50°C to 150°C) at which the organic solvent is removed and sintering of the first ceramic powder does not occur.

[0076] The firing process involves, for example, applying heat treatment (firing) to the laminate L. This burns away the organic components, including the binder resin, and sinters the inorganic powder contained in each layer, fixing it to the surface of the substrate S, or to the surface of the metal layer M and the surface of the second ceramic layer C2. As a result, an electronic component having a fired film of the first ceramic ink (in this case, an electronic component having a fired laminate L) is manufactured. The firing temperature is preferably set to, for example, 500°C to 2000°C.

[0077] In the laminate L shown in Figure 1, a second ceramic layer C2 is provided, but depending on the type of electronic component, the second ceramic layer C2 may not be necessary. In this case, the second printing step and the second drying step in the manufacturing method described above may be omitted.

[0078] Next, we will describe some test examples relating to the technology disclosed herein. Note that the following test examples are not intended to limit the scope of the technology disclosed herein.

[0079] [Prepare the materials] (Ceramic powder) The following ceramic powders were prepared. Note that the average particle sizes listed below are the manufacturer's stated values. BT1: Barium titanate powder with an average particle size of 50 nm (Kyoritsu Material Co., Ltd.) ·BT2: Barium titanate powder with an average particle size of 100 nm (Kyoritsu Material Co., Ltd.) BT3: Barium titanate powder with an average particle size of 300 nm (Kyoritsu Material Co., Ltd.) ·alumina: Alumina powder with an average particle size of 120 nm (Daimyo Chemical Industry Co., Ltd.) ·BZCYY: BaZr with an average particle size of 200 nm 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ Powder (Kyoritsu Material Co., Ltd.)

[0080] (Organic solvents) The following nine types of organic solvents were prepared. The physical properties of these organic solvents are shown in Table 1. Of the physical properties shown in Table 1, the boiling point (boiling point under atmospheric pressure conditions) is the nominal value from each manufacturer. The SP value of each organic solvent shown in Table 1 was calculated using the Fedors method described above. The surface tension of each organic solvent shown in Table 1 is the measured value for each organic solvent using a static surface tensimeter (DYNEMASTER DY-300, manufactured by Kyowa Interface Science Co., Ltd.).

[0081] • Organic solvent S1: Ethylene glycol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., CAS No. 107-21-1 • Organic solvent S2: Glycerin, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., CAS No. 56-81-5 • Organic solvent S3: Dimethyl sulfoxide (DMSO), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., CAS No. 67-68-5 • Organic solvent S4: 1,3-Propanediol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., CAS No. 504-63-2 • Organic solvent S5: 1-Hexanol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., CAS No. 111-27-3 • Organic solvent S6: Benzyl alcohol, manufactured by Kanto Chemical Co., Ltd., CAS No. 100-51-6 • Organic solvent S7: Butyl diglycol acetate (BDGAC), manufactured by Daicel Corporation, CAS No. 124-17-4 • Organic solvent S8: 2,2,4-Trimethyl-1,3-pentanediol 1-monoisobutyrate (NG-120), CAS No. 25265-77-4 • Organic solvent S9: Diethylene glycol butyl methyl ether (Hysolve BDM), manufactured by Toho Chemical Industry Co., Ltd., CAS No. 7382-32-3

[0082] [Table 1]

[0083] (Binder resin) Two types of binder resins were prepared as binder resins. Binder resin B1: Polyvinyl butyral resin with 32 mol% hydroxyl groups and a weight-average molecular weight of 18,000 (manufactured by Sekisui Chemical Co., Ltd., "BX-L") Binder resin B2: Polyvinyl butyral resin with 23 mol% hydroxyl groups and a weight-average molecular weight of 23,000 (manufactured by Sekisui Chemical Co., Ltd., "BL-S").

[0084] (Dispersant) As a dispersant, a cationic dispersant (manufactured by NOF Corporation, "AD-374M") was prepared.

[0085] [Ink preparation] Twenty-one types of inks were prepared, each containing ceramic powder, binder resin, dispersant, and organic solvent. First, the ceramic powder and organic vehicle (organic solvent, binder resin, and dispersant) were mixed in a predetermined mass ratio to prepare a slurry. This slurry was then subjected to a crushing and dispersion treatment using crushing beads (zirconia beads with an average particle size of 30 μm) (rotation speed: 1500 rpm, mixing time: 16 hours), and the ink was obtained by filter filtration under pressure. The ceramic powder, binder resin, and organic solvent used in each example are shown in the corresponding columns of Tables 2 and 3. Where necessary, the cationic dispersant described above was used as the dispersant. The evaluation results for each ink prepared in this test example are shown in Tables 2 and 3. Note that in the preparation of the ink in Example 16, the above-described filter filtration under pressure could not be performed. Therefore, the following evaluation test was not performed on Example 16.

[0086] Regarding ceramic powder, the values ​​listed in Tables 2 and 3 represent the content (mass%) when the total ink is considered to be 100% by mass. Regarding binder resin and dispersant, the values ​​listed in Tables 2 and 3 represent the content (mass%) when the organic vehicle is considered to be 100% by mass. Regarding binder resin, in cases where neither binder resin B1 nor binder resin B2 is included, "-" is indicated in the corresponding column. Regarding organic solvents, the values ​​listed in Tables 2 and 3 represent the volume ratio of each organic solvent when the total organic solvent is considered to be 100% by volume. Regarding organic solvents, the "weighted average SP value" listed in Tables 2 and 3 is the sum of the products of the SP value of each organic solvent and the composition ratio (volume ratio) of each organic solvent (weighted average value).

[0087] [Table 2]

[0088] [Table 3]

[0089] [Evaluation Test] A. Ink characteristics (A-1) Viscosity The viscosity (mPa·s) of each ink sample was measured using a B-type viscometer (Brookfield, DV-III ULTRA spindle SC4-14) while maintaining the ink at 25°C. The rotor speed of the B-type viscometer was set to 10 rpm. The results are shown in Tables 2 and 3. Here, inks with a viscosity of 30 mPa·s or less were evaluated as having appropriate viscosity for the inkjet head.

[0090] (A-2) Average particle diameter The average particle size of the particles contained in the ink was measured using dynamic light scattering (DLS) spectroscopy. The results are shown in Tables 2 and 3. In this study, inks with an average particle size of 20 nm to 320 nm were evaluated as having good dispersibility of the ceramic powder. For Examples 15 and 17, where the average particle size exceeded 320 nm, the following tests were not performed.

[0091] (A-3) Daily measurement (measurement of daily stability) After preparation, a portion of the ink was collected in two storage bottles. One bottle was stored at 25°C and the other at 60°C. The average particle size of each ink, stored at 1 week, 2 weeks, 3 weeks, 4 weeks, and 8 weeks, was measured using dynamic light scattering (DLS) spectroscopy. The results are shown in Tables 2 and 3. Here, for both the 25°C and 60°C environments, an average particle size of 20 nm to 320 nm after 2 weeks was evaluated as "○ (good stability over time)," and anything outside this range was evaluated as "× (poor stability over time)." Note that the ink in Example 14 was evaluated as "×," so the following evaluations of resin solubility and sheet attack properties were not performed for this example.

[0092] (A-4) Surface tension The surface tension (mN / m) of the ink was measured using the static surface tensimeter described above. Inks with a surface tension in the range of 25 (mN / m) to 35 (mN / m) were evaluated as having good surface tension. The results are shown in Tables 2 and 3.

[0093] (A-5) Resin solubility The solubility of resin binder B1 in the organic solvents used in the inks of each example was evaluated. The organic solvents contained in the inks of each example were prepared, and polyvinyl butyral resin (Sekisui Chemical Co., Ltd. "BX-L") was dissolved in them at a concentration of 1% by weight while being heated to 90°C. The solution was then cooled to 5°C. When the solution temperature reached 5°C, the presence or absence of resin precipitation was visually observed. Here, if no resin precipitation occurred, it was judged as "○ (resin solubility present)," and if resin precipitation occurred, it was judged as "× (resin solubility absent)." The results are shown in Tables 2 and 3.

[0094] C. Evaluation of seat attack performance The organic solvent contained in the inks of each example was prepared and heated to 90°C. Polyvinyl butyral resin (BL-5Z, manufactured by Sekisui Chemical Co., Ltd.) (a polyvinyl butyral resin containing 21 mol% hydroxyl groups and with a weight-average molecular weight of 32,000) was dissolved in it at a concentration of 1% by weight. This solution was cooled to 60°C. When the solution temperature reached 60°C, the presence or absence of resin precipitation was visually observed. If resin precipitation occurred (i.e., the resin was not dissolved in the organic solvent at a temperature of 60°C), it was determined that there was no sheet attack property. If no resin precipitation occurred, it was determined that there was sheet attack property. The sheet attack property against acrylic resin (BR-105, manufactured by Mitsubishi Chemical Corporation) was evaluated using the same procedure. If it was determined that there was no sheet attack property against both the polyvinyl butyral resin and the acrylic resin described above, it was evaluated as "none (no sheet attack property)". On the other hand, if sheet attack properties were determined to be present with respect to either the polyvinyl butyral resin or the acrylic resin mentioned above, it was evaluated as "yes (sheet attack properties present)". The results are shown in Tables 2 and 3.

[0095] As shown in Tables 2 and 3, the inks of Examples 1-9, 18, and 19 were evaluated as having no sheet attack properties when using the polyvinyl butyral resin and acrylic resin used in item C above in the sheet attack evaluation test. Here, the inks of Examples 1-9, 18, and 19 were non-aqueous inks containing a first ceramic powder, a binder resin, and an organic solvent. The organic solvent contained dimethyl sulfoxide, alkanediol, and saturated monohydric alcohol. The Fedors SP value of the entire organic solvent was 13.5 (cal / cm³). 3 ) 1 / 2 More than 14.5(cal / cm 3 ) 1 / 2The following was observed. In particular, the inks in Examples 1 to 7 do not contain dispersants, while the inks in Examples 8 and 9 do. In this regard, even without a dispersant in the ink, good evaluations were obtained in terms of viscosity, average particle size, long-term stability, and surface tension. For this reason, the inks disclosed herein do not require the inclusion of a dispersant. In such embodiments, for example, it is expected that the shape retention effect of the printed film of the ink will be enhanced.

[0096] The technologies disclosed herein have been described above, but these are merely examples and do not limit the scope of the claims. The technologies disclosed herein may be modified in various ways without departing from their essence.

[0097] The technologies disclosed herein include the technologies described in the following sections. Section 1: Inkjet ink used in the manufacture of electronic components, It is a non-aqueous system, First ceramic powder and Binder resin, Organic solvents and Includes, The aforementioned organic solvent comprises dimethyl sulfoxide, an alkanediol, and a saturated monohydric alcohol. The Fedors SP value for the entire organic solvent is 13.5 (cal / cm³). 3 ) 1 / 2 More than 14.5(cal / cm 3 ) 1 / 2 The following are inkjet inks. Section 2: The inkjet ink according to item 1, wherein the binder resin comprises a polyvinyl butyral resin containing at least 28 mol% hydroxyl groups. Section 3: The inkjet ink according to claim 1 or 2, wherein the alkanediol is at least one of ethylene glycol and 1,3-propanediol. Section 4: The inkjet ink according to any one of items 1 to 3, wherein the saturated monohydric alcohol is 1-hexanol. Section 5: An inkjet ink that is substantially free of dispersants, as described in any one of items 1 to 4. Item 6: The inkjet ink according to any one of items 1 to 5, wherein the average particle size of the ceramic powder based on dynamic light scattering is 10 nm or more and 400 nm or less. Section 7: The first ceramic powder is barium titanate powder, alumina powder, and BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ An inkjet ink according to any one of items 1 to 6, which is at least one selected from the group consisting of powders. Section 8: An ink set used in the manufacture of electronic components, A first ceramic inkjet ink, which is an inkjet ink described in any one of items 1 to 7, conductive inkjet ink, Includes, The conductive inkjet ink is an ink set comprising metal powder, polyvinyl butyral resin containing less than 28 mol% hydroxyl groups, a dispersant, and an organic solvent. Section 9: Furthermore, it includes a second ceramic inkjet ink, The ink set according to item 8, wherein the second ceramic inkjet ink comprises a second ceramic powder, a thermoplastic resin, a dispersant, and an organic solvent. Section 10: A method for manufacturing electronic components, A printed film of conductive inkjet ink is provided on the surface of the substrate, The printed film of the conductive inkjet ink is laminated with a printed film of a first ceramic inkjet ink, which is an inkjet ink described in any one of items 1 to 7. The laminate comprising the substrate, the printed film of the conductive inkjet ink, and the printed film of the first ceramic inkjet ink is subjected to heat treatment. It includes, A method for producing the conductive inkjet ink comprising metal powder, a polyvinyl butyral resin containing less than 28 mol% hydroxyl groups, a dispersant, and an organic solvent. Section 11: Furthermore, the method includes providing a second ceramic inkjet ink print film adjacent to the conductive inkjet ink print film on the surface of the substrate, The first ceramic inkjet ink print film is laminated on the conductive inkjet ink print film and the second ceramic inkjet ink print film. The method for producing the second ceramic inkjet ink according to item 10, comprising a second ceramic powder, a thermoplastic resin, a dispersant, and an organic solvent. [Explanation of symbols]

[0098] 1. Inkjet device 10 inkjet heads 12 cases 13 Storage section 15. Fluid delivery routes 16 Discharge part 17 Outlet 18 Piezo elements 20 Guide axis 40 Print Cartridges 100 Mixing and Grinding Machine 110 Supply port 120 stirring vessel 132 Agitator blades 134 shaft 140 filters 150 Outlet

Claims

1. Inkjet ink used in the manufacture of electronic components, It is a non-aqueous system, First ceramic powder and Binder resin, Organic solvents and Includes, The aforementioned organic solvent comprises dimethyl sulfoxide, an alkanediol, and a saturated monohydric alcohol. The Fedors SP value for the entire organic solvent is 13.5 (cal / cm³). ３ ) １／２ More than 14.5 (cal / cm ３ ) １／２ The following are inkjet inks.

2. The inkjet ink according to claim 1, wherein the binder resin comprises a polyvinyl butyral resin containing at least 28 mol% hydroxyl groups.

3. The inkjet ink according to claim 1, wherein the alkanediol is at least one of ethylene glycol and 1,3-propanediol.

4. The inkjet ink according to claim 1, wherein the saturated monohydric alcohol is 1-hexanol.

5. The inkjet ink according to claim 1, which is substantially free of dispersants.

6. The inkjet ink according to claim 1, wherein the average particle size of the ceramic powder based on dynamic light scattering is 10 nm or more and 400 nm or less.

7. The first ceramic powder is at least one selected from the group consisting of barium titanate powder, alumina powder, and BaZr ０．１ Ce ０．７ Y ０．１ Yb ０．１ O ３－δ The inkjet ink according to claim 1, which is at least one selected from the group consisting of powders.

8. An ink set used in the manufacture of electronic components, A first ceramic inkjet ink which is an inkjet ink according to any one of claims 1 to 7, conductive inkjet ink, Includes, The conductive inkjet ink is an ink set comprising metal powder, polyvinyl butyral resin containing less than 28 mol% hydroxyl groups, a dispersant, and an organic solvent.

9. Furthermore, it includes a second ceramic inkjet ink, The ink set according to claim 8, wherein the second ceramic inkjet ink comprises a second ceramic powder, a thermoplastic resin, a dispersant, and an organic solvent.

10. A method for manufacturing electronic components, A printed film of conductive inkjet ink is provided on the surface of the substrate, A printed film of a first ceramic inkjet ink, which is an inkjet ink according to any one of claims 1 to 7, is laminated onto the printed film of the conductive inkjet ink. The laminate comprising the substrate, the printed film of the conductive inkjet ink, and the printed film of the first ceramic inkjet ink is subjected to heat treatment. It includes, The conductive inkjet ink comprises a metal powder, a polyvinyl butyral resin containing less than 28 mol% of hydroxyl groups, a dispersant, and an organic solvent, and is manufactured using a method for this method.

11. Furthermore, the method includes providing a second ceramic inkjet ink print film adjacent to the conductive inkjet ink print film on the surface of the substrate, The first ceramic inkjet ink print film is laminated on the conductive inkjet ink print film and the second ceramic inkjet ink print film. The manufacturing method according to claim 10, wherein the second ceramic inkjet ink comprises a second ceramic powder, a thermoplastic resin, a dispersant, and an organic solvent.

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