KR102658648B1 - Photosensitive composition and its use - Google Patents

Abstract

According to the present invention, a photosensitive composition containing a conductive powder, a photopolymerizable compound, and a photopolymerization initiator is disclosed. The photopolymerization initiator includes at least the following two types of components: (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide; (2) α-aminoalkylphenones; and when the total of the photopolymerization initiators is 100% by mass, (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is 50% by mass. It occupies more than

Description

Photosensitive composition and its use

The present invention relates to photosensitive compositions and their uses.

In addition, this application claims priority based on Japanese Patent Application No. 2018-021134 filed on February 8, 2018, the entire contents of which are incorporated herein by reference.

Conventionally, a method of forming a conductive layer or a resin insulating layer on a substrate by photocuring using a photosensitive composition containing a photopolymerizable compound and a photopolymerization initiator is known (see Patent Documents 1 to 6). For example, Patent Document 1 discloses forming a wiring pattern on a substrate by a photolithography method including a film forming process, an exposure process, a developing process, and a baking process. In this method, first, in the forming process of the film-like body, the photosensitive composition is applied to the substrate by a printing method or the like, and then dried to form the film-like body. Next, in the exposure process, a photomask having a predetermined opening pattern is covered over the molded film body, and then the film body is exposed through the photomask. In this way, the exposed portion of the film-like body is photocured. Next, in the development process, the unexposed portion that was shielded from light by the photomask is removed by etching with an alkaline etching solution. Then, the film-like body with the desired development pattern is fired in a baking step. According to this method, compared to various conventional printing methods, a conductive layer with a high-precision pattern can be formed.

Patent Document 1: Japanese Patent No. 4437603 Patent Document 2: Japanese Patent No. 4095163 Patent Document 3: Japanese Patent Application Publication No. 2003-183401 Patent Document 4: Japanese Patent Application Publication No. 2015-110745 Patent Document 5: Japanese Patent Application Publication No. 2015-184631 Patent Document 6: Japanese Patent No. 5393402

However, in recent years, miniaturization and high performance of various electronic devices have progressed rapidly, and further miniaturization and higher density of electronic components mounted on electronic devices have been required. Along with this, in the manufacture of electronic components, thinning of the conductive layer along with lower resistance is required. For example, it is required to form a conductive layer containing fine wires (hereinafter sometimes referred to as “fine lines”) with a line width of 30 μm or less.

However, according to the present inventors' examination, it was difficult to stably form a fine line when using the conventional photosensitive composition described in the above patent document. For example, there were cases where unexposed portions were not completely removed during the development process, and neighboring wires were connected to each other, resulting in short circuit defects. Additionally, if the development process time is set to be long in order to suppress the occurrence of such short circuit defects, the exposed portion becomes thin, which may cause peeling or disconnection in the development pattern.

One cause of the above-mentioned problem may be that the development margin is short. Here, the “development margin” refers to the time from the point at which the unexposed portion is completely removed (break point (B.P.)) in the developing process until an abnormality such as peeling or disconnection occurs in the exposed portion constituting the developing pattern. It indicates the length of . In other words, if the development margin is not sufficiently secured, thinning or loss occurs in the exposed portion immediately after the unexposed portion is removed. For this reason, it is difficult to determine the timing for completing the development process, especially when forming a fine line. Therefore, in process management, there is a need for technology that can secure a long development margin (for example, 10 seconds or more) and form a fine line with good reproducibility.

The present invention was made in view of these points, and its purpose is to provide a photosensitive composition that has a long development margin and can stably form fine lines. Additionally, another related object is to provide a composite having a conductive film made of a dried product of such a photosensitive composition. Additionally, another related object is to provide an electronic component including a conductive layer made of a sintered body of such a photosensitive composition, and a method for manufacturing the same.

According to the present invention, a photosensitive composition used to produce a conductive layer containing wiring with a line width of 30 μm or less is provided. This photosensitive composition contains conductive powder, a photopolymerizable compound, and a photopolymerization initiator. The photopolymerization initiator includes at least the following two types of components: (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide; (2) α-aminoalkylphenones; and when the total of the photopolymerization initiators is 100% by mass, (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is 50% by mass. It occupies more than

The photosensitive composition contains at least two types of components (1) and (2) as a photopolymerization initiator. As a result, it is possible to secure a long development margin time in the development process and improve fine line formation in the exposed portion. As a result, even fine lines with a line width of 30 μm or less can be formed with good reproducibility. In addition, the occurrence of abnormalities such as short circuit defects, peeling, and disconnection can be suppressed, thereby improving yield.

In a preferred embodiment disclosed herein, the mass ratio of (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and (2) α-aminoalkylphenone is 50:50 to 90:10. am. As a result, fine line formation can be further improved, and the effect of the technology disclosed here can be exhibited at a higher level. For example, even if the conductive layer has more advanced fine lines, it can be formed with high precision.

In a preferred embodiment disclosed herein, the mass ratio of (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and (2) α-aminoalkylphenones is 50:50 to 85:15. am. As a result, the etching resistance of the exposed portion can be further improved, and peeling of the conductive layer can be suppressed to a higher level.

In a preferred embodiment disclosed herein, when the total of the photosensitive composition is 100% by mass, the proportion of the photopolymerization initiator is 2% by mass or less. This provides at least one of the following effects: ensuring a longer development margin time and improving fine line formation properties.

In a preferred embodiment disclosed herein, the photopolymerizable compound includes a photopolymerizable compound having a urethane bond. As a result, the conductive film made of the dried photosensitive composition can be made to have excellent flexibility and elasticity. Additionally, the etching resistance of the exposed portion can be further improved. As a result, the adhesion between the base material and the conductive layer is improved, and the occurrence of abnormalities such as peeling can be suppressed to a higher level.

In a preferred embodiment disclosed here, the conductive powder contains silver-based particles. As a result, a conductive layer with an excellent balance between cost and low resistance can be realized.

In a preferred embodiment disclosed herein, the conductive powder includes a core portion containing a metal material, a core shell particle that covers at least a portion of the surface of the core portion, and has a coating portion containing a ceramic material. As a result, the etching resistance of the exposed portion can be further improved while the fine line formation property can be further improved. Additionally, in the application of manufacturing a ceramic electronic component including a conductive layer on a ceramic substrate (ceramic substrate), the durability of the ceramic electronic component can be improved by increasing the integrity of the ceramic substrate and the conductive layer.

In a preferred embodiment disclosed herein, in the L ^* a ^* b ^* colorimetric system based on Japanese Industrial Standards JIS Z 8781: 2013, the brightness L ^* of the conductive powder is 50 or more. As a result, in the exposure process, light stably reaches the deep portion of the exposed portion, and a thick conductive layer can be stably realized.

In a preferred embodiment disclosed herein, the photosensitive composition further contains an organic solvent having a boiling point of 150°C or higher and 250°C or lower. As a result, the drying temperature after printing can be suppressed low while improving the storage stability of the photosensitive composition and the handleability during formation of the conductive film.

Furthermore, the present invention provides a composite comprising a green sheet and a conductive film disposed on the green sheet and made of a dried body of the photosensitive composition.

Furthermore, according to the present invention, an electronic component provided with a conductive layer made of a sintered body of the photosensitive composition is provided. According to the photosensitive composition, fine lines can be stably realized. For this reason, electronic components with small and/or high-density conductive layers can be suitably realized.

Furthermore, the present invention provides a method for manufacturing an electronic component, comprising the step of applying the photosensitive composition onto a substrate, exposing and developing it, and then baking it to form a conductive layer made of a sintered body of the photosensitive composition. do. The photosensitive composition ensures a long development margin. Therefore, by this manufacturing method, electronic components with small and/or high-density conductive layers can be manufactured stably, and the yield can be improved.

[Figure 1] Figure 1 is a cross-sectional view schematically showing the structure of a multilayer chip inductor according to an embodiment.
[Figure 2] Figure 2 is a graph showing the relationship between the content ratio of the initiator (c) and the line width of the wiring pattern.

Hereinafter, preferred embodiments of the present invention will be described. In addition, matters other than those specifically mentioned in this specification (e.g., photopolymerization initiator included in the photosensitive composition) are necessary for practicing the present invention (e.g., method of preparing the photosensitive composition, conductive film or conductive layer). formation method, manufacturing method of electronic components, etc.) can be understood based on the technical content taught in this specification and the general technical knowledge of those skilled in the art. The present invention can be implemented based on the content disclosed in this specification and common technical knowledge in the field.

In addition, in the following description, a film-like body (dried product) obtained by drying the photosensitive composition at a temperature below the boiling point of the photopolymerizable compound and the photopolymerization initiator, specifically, approximately 200°C or below, for example, 100°C or below, is referred to as a “conductive film.” “It is said. The conductive film includes the entire unbaked (before firing) film-like body. The conductive film may be an uncured product before photocuring, or may be a cured product after photocuring. In addition, in the following description, the sintered body (fired product) obtained by baking the photosensitive composition at a temperature higher than the sintering temperature of the conductive powder is referred to as a “conductive layer.” The conductive layer contains wiring (linear body) and a wiring pattern.

In addition, in this specification, the notation “A to B” indicating a range means A to B or less.

≪Photosensitive composition≫

The photosensitive composition disclosed herein is used to produce a conductive layer containing fine line wiring whose line width after firing is 30 μm or less. For example, it is preferably used for forming a conductor film including a portion with a line width of 30 μm or less. The photosensitive composition disclosed herein contains conductive powder, a photopolymerizable compound, and a photopolymerization initiator as essential components. Hereinafter, each component will be described in order.

<Conductive powder>

Conductive powder is a component that provides electrical conductivity to the conductive layer obtained by baking the photosensitive composition. The conductive powder is not particularly limited, and one or two or more types can be appropriately selected and used among conventionally known powders, for example, depending on the intended use. Suitable examples of conductive powder include gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), aluminum (Al), nickel (Ni), ruthenium (Ru), and rhodium (Rh). ), tungsten (W), iridium (Ir), osmium (Os), and other metals alone, and mixtures or alloys thereof. Examples of the alloy include silver alloys such as silver-palladium (Ag-Pd), silver-platinum (Ag-Pt), and silver-copper (Ag-Cu).

In one suitable embodiment, the conductive powder includes silver-based particles. Silver is relatively cheap and has high electrical conductivity. For this reason, when the conductive powder contains silver-based particles, a conductive layer with an excellent balance between cost and low resistance can be realized. In addition, in this specification, “silver particles” include everything containing a silver component. Examples of silver-based particles include silver alone, the above-mentioned silver alloy, and core-shell particles using silver-based particles as the core.

In another suitable embodiment, the conductive powder comprises core shell particles of metal-ceramic. Metal-ceramic core-shell particles have a core portion containing a metal material, a surface of the core portion covering at least a portion, and a coating portion containing a ceramic material. Ceramic materials are excellent in chemical stability, heat resistance, and durability. For this reason, by adopting the form of metal-ceramic core-shell particles, the stability of the conductive powder in the photosensitive composition can be further improved. In addition, fine line formation can be further improved. Additionally, in the application of manufacturing ceramic electronic components, the durability of the ceramic electronic component can be improved by increasing the unity and adhesion between the ceramic substrate and the conductive layer.

In metal-ceramic core-shell particles, metal materials constituting the core portion include, for example, the above-mentioned metals alone and mixtures or alloys thereof. Among them, silver-based particles are preferable for the reasons described above. In other words, it is preferable that the conductive powder contains silver-ceramic core-shell particles.

The ceramic material constituting the covering portion is not particularly limited, but examples include zirconium oxide (zirconia), magnesium oxide (magnesia), aluminum oxide (alumina), silicon oxide (silica), titanium oxide (titania), and cerium oxide. oxide-based materials such as (ceria), yttrium oxide (yttria), and barium titanate; Complex oxide-based materials such as cordierite, mullite, forsterite, steatite, sialon, zircon, and ferrite; Nitride-based materials such as silicon nitride (silicon nitride) and aluminum nitride (alumina nitride); Carbide-based materials such as silicon carbide (silicon carbide); Hydroxide-based materials such as hydroxyapatite; etc. can be mentioned. For example, in the application of manufacturing ceramic electronic components by forming a conductive layer on a ceramic substrate, a ceramic material of the same type or a type with excellent affinity as the ceramic substrate is preferable.

Although not particularly limited, the content ratio of the ceramic material in the metal-ceramic core-shell particles may be, for example, 0.01 to 5.0 parts by mass per 100 parts by mass of the metal material of the core portion. In addition, metal-ceramic core-shell particles can be produced according to conventionally known methods. For example, as described in paragraphs 0025 to 0028 of Japanese Patent No. 5075222, the applicant of the present application, a metal material and an organic metal compound (for example, a metal alkoxide or chelate compound) or oxide sol containing the desired metal element are used. It can be produced by reacting.

Although not particularly limited, the D ₅₀ particle size of the conductive powder may be approximately 1.0 to 5.0 μm in balance with the exposure performance in the exposure process. By setting the D ₅₀ particle size within the above range, the exposure performance of the exposed portion can be improved, and a fine line can be formed more stably. In addition, in this specification, “D ₅₀ particle size” refers to the particle size equivalent to 50% of the integrated value from the smallest particle size in the volume-based particle size distribution based on the laser diffraction/scattering method.

From the viewpoint of suppressing aggregation in the photosensitive composition and improving stability, the D ₅₀ particle size of the conductive powder may be, for example, 1.5 μm or more, 2.0 μm or more, or 2.5 μm or more. Additionally, from the viewpoint of improving fine wire formation or advancing densification or lowering of resistance of the conductive layer, the D ₅₀ particle size of the conductive powder may be, for example, 4.5 μm or less or 4.0 μm or less.

Although it is not particularly limited, the particle size distribution of the entire conductive powder may be multimodal. In other words, the first conductive powder and the second conductive powder having different D ₅₀ particle sizes may be included. As a result, compared to the case where the difference in D ₅₀ particle size between the first conductive powder and the second conductive powder is small, the electrical resistance can be appropriately reduced while improving the density and filling properties of the conductive layer. The D ₅₀ particle diameters of the first conductive powder and the second conductive powder should be separated by at least 0.5 μm, typically 0.5 to 3.0 μm, for example, about 1.0 to 2.0 μm. In one specific example, the D ₅₀ particle size of the first conductive powder is in the range of approximately 3 to 5 μm, for example, 3.5 to 4.5 μm, and the D ₅₀ particle size of the second conductive powder is approximately 1 to 3.5 μm, For example, it should be in the range of 1.5 to 3 μm.

Although not particularly limited, the shape of the conductive particles constituting the conductive powder is typically approximately spherical with an average aspect ratio (major axis/minor axis ratio) of approximately 1 to 2, preferably 1 to 1.5, for example. The idea is for 1 to 1.2 people. Thereby, exposure performance can be realized more stably. The conductive powder should just have an average aspect ratio within the above range. In addition, in this specification, “average aspect ratio” refers to the arithmetic average value of the aspect ratio calculated from the observation images obtained by observing a plurality of conductive particles with an electron microscope. In addition, in this specification, “spherical” refers to a shape that can be viewed as a general sphere (ball), and is a term that can include an elliptical shape, a polygonal shape, a disk sphere, etc.

Although not particularly limited, the entire conductive powder may have a brightness L ^* of 50 or more in the L ^* a ^* b ^* color system based on Japanese Industrial Standards JIS Z 8781:2013. As a result, in the exposure process, the irradiated light stably reaches the deep part of the exposed portion, and a conductive layer as thick as, for example, 5 μm or more, and even 10 μm or more, can be stably realized. From this viewpoint, the brightness L ^* of the conductive powder may be approximately 55 or more, for example, 60 or more. The brightness L ^* can be adjusted, for example, by the type of the above-described conductive powder or the D ₅₀ particle size. In addition, the measurement of brightness L ^* can be performed, for example, with a spectrophotometer compliant with Japanese Industrial Standards JIS Z 8722: 2009.

Additionally, the conductive powder may have an organic surface treatment agent adhering to its surface. The organic surface treatment agent is at least one of, for example, improving the dispersibility of the conductive powder in the photosensitive composition, enhancing affinity with other components, and preventing surface oxidation of the metal constituting the conductive powder. It can be used for various purposes. Examples of organic surface treatment agents include fatty acids such as carboxylic acid and benzotriazole-based compounds.

Although not particularly limited, the proportion of the conductive powder in the entire photosensitive composition may be approximately 50% by mass or more, typically 60 to 95% by mass, for example, 70 to 90% by mass. By satisfying the above range, a conductive layer with excellent density and electrical conductivity can be suitably formed. Additionally, the handling of the photosensitive composition and workability when forming a conductive film can be improved.

<Photopolymerizable compound>

A photopolymerizable compound is a component that polymerizes and hardens by active species generated by decomposition of a photopolymerization initiator, which will be described later. The polymerization reaction may be addition polymerization or ring-opening polymerization. Photopolymerizable compounds typically have one or more unsaturated bonds and/or cyclic structures. Photopolymerizable compounds include monomers, polymers, and oligomers. Among them, monomers are preferable. The photopolymerizable compound is not particularly limited, and one or two or more types can be appropriately selected and used from among conventionally known compounds, for example, depending on the intended use or type of substrate. Suitable examples of photopolymerizable compounds include radically polymerizable monomers having one or more unsaturated bonds such as a (meth)acryloyl group or vinyl group, and cationically polymerizable monomers having a cyclic structure such as an epoxy group.

In one suitable embodiment, the photopolymerizable compound contains a (meth)acrylate monomer having a (meth)acryloyl group. By containing a (meth)acrylate monomer, the flexibility of the conductive layer and its conformability to the substrate can be improved. As a result, the occurrence of abnormalities such as peeling and disconnection can be suppressed to a much higher level. In addition, in this specification, “(meth)acryloyl” includes “methacryloyl” and “acryloyl”, and “(meth)acrylate” includes “methacrylate” and “acrylic”. It is a term that includes “rate.” In addition, (meth)acrylate monomers include monofunctional (meth)acrylates having one functional group per molecule, polyfunctional (meth)acrylates having two or more functional groups per molecule, and their modified products. do.

Suitable examples of (meth)acrylate monomers include triethylene glycol monoacrylate, triethylene glycol monomethacrylate, tetraethylene glycol monoacrylate, tetraethylene glycol monomethacrylate, pentaerythritol triacrylate, and pentaerythate. Litol trimethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol heptaacrylate, tripentaerythritol octaacrylate, tetrapentaerythritol nonacrylate, tetrapentaerythritol and polyfunctional (meth)acrylates such as decaacrylate. Among these, from the viewpoint of improving photocurability, monomers having 5 or more (meth)acryloyl groups per molecule are preferable.

In another suitable embodiment, the photopolymerizable compound includes a photopolymerizable compound (urethane bond-containing compound) having a urethane bond (-NH-C(=O)-O-). As a result, a conductive layer with excellent flexibility and elasticity can be realized while further improving the etching resistance of the exposed portion. Accordingly, the adhesion between the base material and the conductive layer is improved, and the occurrence of abnormalities such as peeling and disconnection can be suppressed to a higher level. Suitable examples of the urethane bond-containing compound include urethane-modified (meth)acrylate and urethane-modified epoxy. The proportion of the urethane bond-containing compound in the entire photopolymerizable compound is more preferably approximately 30% by mass or more, typically 50% by mass or more, for example, 95% by mass or more, and may be substantially 100% by mass. do.

Although not particularly limited, the weight average molecular weight of the photopolymerizable compound may be approximately 100 to 10000, typically 200 to 5000, for example 300 to 2000. In addition, in this specification, “weight average molecular weight” refers to the average molecular weight based on weight measured by gel chromatography (Gel Permeation Chromatography: GPC) and converted using a standard polystyrene calibration curve. When the photopolymerizable compound is a monomer, the molecular weight is the same.

Although not particularly limited, the proportion of the photopolymerizable compound in the entire photosensitive composition is approximately 0.1 to 20% by mass, typically 0.5 to 10% by mass, for example 2 to 8% by mass, and further 3 to 6% by mass. It can be %. By satisfying the above range, the photocurability of the photosensitive composition is sufficiently exhibited, and a conductive layer can be formed stably at a higher level.

<Photopolymerization initiator>

A photopolymerization initiator is a component that initiates the polymerization reaction of a photopolymerizable compound by decomposing it upon irradiation of light energy such as ultraviolet rays to generate active species such as radicals and cations. In the photosensitive composition disclosed herein, the photopolymerization initiator includes at least the following two types of components: (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide; (2) α-aminoalkylphenone; is included as essential.

The photopolymerization initiators (1) and (2) above typically have different absorption wavelengths. Therefore, by using these together, the absorption wavelength range spreads and active species can be generated with high efficiency compared to the case where one type of photopolymerization initiator is used alone. In addition, due to the synergistic effect of the photopolymerization initiators (1) and (2) above, in the development process, for example, the time until the break point (B.P.) remains the same as before, and a long development margin time can be secured. . Due to the above-mentioned effects, the technology disclosed herein improves the ability to form fine lines, and allows the formation of fine lines with good reproducibility even if the line width is 30 μm or less. Hereinafter, the photopolymerization initiators (1) and (2) will be described.

(1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is monoacyl phosphine oxide (MAPO). Commercially available products include DAROCUR (trademark) TPO and IRGACURE (trademark) TPO (all manufactured by BASF Japan Co., Ltd.). Acyl phosphine oxide-based photopolymerization initiators have excellent compatibility with photopolymerizable compounds and organic dispersion media. Therefore, it is effective for improving the storage stability of the photosensitive composition.

In addition, as a photopolymerization initiator classified into the acyl phosphine oxide type as (1) above, bisacyl phosphine oxide (BAPO), for example, bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide, is included. You can. However, as shown in the test examples described later, when bisacyl phosphine oxide is used instead of (1) above, the effects of the technology disclosed herein as described above are not exhibited. In other words, it can be said that there is specificity in the combined use of the photopolymerization initiators of (1) and (2) above.

In the technology disclosed herein, the above (1) serves as the main photopolymerization initiator. In other words, when the total photopolymerization initiator is 100% by mass, the ratio of (1) above accounts for 50% by mass or more. As a result, fine line formation is improved and fine lines can be appropriately formed. From this viewpoint, the ratio of (1) above may be, for example, 75 mass% or more, preferably 80 mass% or more, and more preferably 85 mass% or more. In addition, from the viewpoint of better demonstrating the synergistic effect with (2) above or improving the adhesion between the base material and the conductive layer, the ratio of (1) above is approximately 90% by mass or less, preferably 85% by mass or less. You can continue.

(2) As α-aminoalkylphenones, any compound having an α-aminoalkylphenone skeleton may be used, and one or two or more types may be appropriately selected and used from among those known in the art. The α-aminoalkylphenone skeleton can be understood, for example, as a functional group having the ability to initiate intramolecular cleavage photopolymerization. The alkyl moiety may be linear or branched. The alkyl moiety may have a substituent. A suitable example of α-aminoalkylphenones includes compounds with a molecular weight of approximately 1000 or less, typically 200 to 500, for example, 250 to 400. Another suitable example is a compound having an α-aminoacetophenone skeleton. A suitable example of a compound having an α-aminoacetophenone skeleton includes a compound having the structural moiety (A) below.

In the above (A), R ¹ and R ² are each independently selected from hydrocarbon groups having 1 to 18 carbon atoms. R ¹ and R ² may be the same or different. R ¹ is, for example, an alkyl group having 1 to 18 carbon atoms. The number of carbon atoms of R ¹ is preferably 1 to 8, typically 1 to 4, for example 1, 2 or 3. R ² is, for example, an alkyl group, an aryl group, or an aryl alkyl group having 1 to 18 carbon atoms. The number of carbon atoms of R ² is preferably 1 to 8. Additionally, R ³ and R ⁴ are each independently selected from a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. R ³ and R ⁴ may be the same or different. For example, R ³ and R ⁴ each independently represent an alkyl group, an aryl group, an aryl alkyl group having 1 to 18 carbon atoms, or a cyclic alkyl ether group in which R ³ and R ⁴ are bonded. The total number of carbon atoms of R ³ and R ⁴ is preferably 1 to 8, typically 1 to 6, for example 2 to 4.

As a specific example of (2) above, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl) butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl] -1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-monopholinopropan-1-one, N,N -Dimethylaminoacetophenone, etc. can be mentioned. Commercially available products include IRGACURE (trademark) 369, IRGACURE (trademark) 379, and IRGACURE (trademark) 907 (all manufactured by BASF Japan Co., Ltd.).

Although not particularly limited, from the viewpoint of demonstrating the effect of the technology disclosed herein at a high level, the ratio of (2) above may be approximately 10 mass% or more when the total photopolymerization initiator is 100 mass%. Additionally, from the viewpoint of improving the adhesion between the base material and the conductive layer, the ratio of (2) above may be 15% by mass or more. Additionally, from the viewpoint of further improving fine wire formation, the ratio of (2) above may be, for example, 25 mass% or less, preferably 20 mass% or less, and more preferably 15 mass% or less.

Although it is not particularly limited, from the viewpoint of demonstrating the effect of the technology disclosed herein at a high level, when the total photopolymerization initiator is 100% by mass, the total ratio of (1) and (2) above is approximately 80% by mass. % or more, preferably 90 mass % or more, more preferably 95 mass % or more, and may be, for example, 100 mass %.

Although not particularly limited, the mass ratio of (1) and (2) above may be approximately 50:50 to 95:5. As a result, fine line formation can be improved, and the effect of the technology disclosed here can be exhibited at a higher level. For example, even if the conductive layer has more advanced fine lines, it can be formed with high precision. In addition, from the viewpoint of further improving the etching resistance of the exposed portion and suppressing peeling of the conductive layer, the mass ratio of (1) and (2) is preferably 50:50 to 90:10, more preferably. It could be 50:50 to 85:15.

Although not particularly limited, the proportion of the photopolymerization initiator in the entire photosensitive composition may be approximately 0.01 mass% or more, typically 0.04 mass% or more, for example, 0.05 mass% or more. As a result, the photocurability of the photosensitive composition is sufficiently exhibited, and a conductive layer can be formed stably. Additionally, the proportion of the photopolymerization initiator in the entire photosensitive composition may be approximately 0.5 mass% or less, typically 0.3 mass% or less, preferably 0.2 mass% or less, for example, 0.1 mass% or less. Thereby, in the development process, the conflicting etching resistance and peelability can be balanced at a higher level. Therefore, a longer development margin time can be ensured, and fine line formation can be better improved.

Although not particularly limited, the content ratio of the photopolymerization initiator may be approximately 0.01 to 1 part by mass, typically 0.02 to 0.2 part by mass, for example, 0.05 to 0.1 part by mass, per 100 parts by mass of the conductive powder. In addition, the content ratio of the photopolymerization initiator is approximately 0.1 to 25 parts by mass, typically 0.2 to 5 parts by mass, for example, 0.5 to 3 parts by mass, and additionally 1 to 2 parts by mass, based on 100 parts by mass of the photopolymerizable compound. It can be a buoy.

<Organic binder>

The photosensitive composition may contain an organic binder in addition to the essential components described above. The organic binder is a component that improves the adhesion between the substrate and the uncured conductive film. As the organic binder, one or two or more types can be appropriately selected and used among conventionally known binders, depending on, for example, the type of substrate, photopolymerizable compound, photopolymerization initiator, etc. As an organic binder, one that can be easily removed with an etchant in the development process is preferable. For example, when using an alkaline etching solution in the development process, hydroxyl group (-OH), carboxyl group (-C(=O)OH), ester bond (-C(=O)O-), Compounds having structural moieties that exhibit acidity, such as porridge (-SO ₃ H), are preferred. This makes it difficult for residues to remain in the unexposed portion, and for example, the space between fine lines can be stably secured.

Suitable examples of organic binders include cellulose-based polymers such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and hydroxymethyl cellulose, acrylic resins, phenol resins, alkyd resins, polyvinyl alcohol, and polyvinyl butyral. . Among them, hydrophilic organic binders such as cellulose polymers and acrylic resins are preferable from the viewpoint of ease of removal in the development process.

When the photosensitive composition contains an organic binder, there is no particular limitation, but the proportion of the organic binder in the entire photosensitive composition is approximately 0.1 to 20% by mass, typically 0.5 to 10% by mass, for example, 1 to 5% by mass. It can be %. In addition, although it is not particularly limited, the content ratio of the photopolymerizable compound and the organic binder may be approximately equal (the difference in the content ratio between the two is approximately 1% by mass or less, for example, 0.5% by mass or less). Thereby, in the development process, the conflicting etching resistance (adhesion) and peelability can be balanced at a higher level.

<Organic dispersion medium>

In addition to the essential components described above, the photosensitive composition may contain an organic dispersion medium that disperses these components. The organic dispersion medium is a component that provides appropriate viscosity and fluidity to the photosensitive composition, improves the handleability of the photosensitive composition, and improves workability when forming a conductive film. As an organic dispersion medium, one or two or more types can be appropriately selected and used among conventionally known ones, depending on, for example, the type of photopolymerizable compound or photopolymerization initiator.

Suitable examples of organic dispersions include alcohol solvents such as terpineol, dihydroterpineol (mentanol), texanol, 3-methyl-3-methoxybutanol, and benzyl alcohol; Glycol-based solvents such as ethylene glycol, propylene glycol, and diethylene glycol; ether-based solvents such as dipropylene glycol methyl ether, methyl cellosolve (ethylene glycol monomethyl ether), cellosolve (ethylene glycol monoethyl ether), and butyl carbitol (diethylene glycol monobutyl ether); Ester systems such as diethylene glycol monobutyl ether acetate, dipropylene glycol methyl ether acetate, butyl glycol acetate, butyl diglycol acetate, butyl cellosolve acetate, butyl carbitol acetate (diethylene glycol monobutyl ether acetate), and isobornyl acetate. solvent; Hydrocarbon solvents such as toluene, xylene, naphtha, and petroleum hydrocarbons; mineral spirits; Organic solvents such as these can be mentioned.

Among these, from the viewpoint of improving the storage stability of the photosensitive composition and the handleability during formation of a conductive film, an organic solvent with a boiling point of 150°C or higher, and further an organic solvent with a boiling point of 170°C or higher, is preferable. Additionally, as another suitable example, from the viewpoint of suppressing the drying temperature after printing the conductive film low, an organic solvent with a boiling point of 250°C or lower, and further an organic solvent with a boiling point of 220°C or lower, is preferable. This makes it possible to reduce production costs while improving productivity.

Additionally, for example, in applications where a conductive layer is formed on a ceramic substrate to manufacture ceramic electronic components, an organic solvent with low permeability into the ceramic green sheet is preferable. Examples of organic solvents with low permeability into the ceramic green sheet include organic solvents with a three-dimensional bulky structure such as a cyclohexyl group or tert-butyl group, and organic solvents with a relatively large molecular weight. Additionally, for example, an organic solvent with low permeability into the ceramic green sheet as described above, and an organic solvent capable of appropriately dissolving components contained in the photosensitive composition (e.g., photopolymerizable material and/or photopolymerization initiator). It is also preferable to mix in an arbitrary ratio and use it as an organic dispersion medium.

Commercially available organic solvents having the above properties (boiling point and permeability into ceramic green sheets) include, for example, Dowanol DPM (trademark) (boiling point: 190°C, manufactured by Dow Chemical Company) and Dowa. Nol DPMA (trademark) (boiling point: 209°C, manufactured by Dow Chemical Company), Menthanol (boiling point: 207°C), Menthanol P (boiling point: 216°C), Isopar H (boiling point: 176°C, Kantonenryo Co., Ltd.) ), SW-1800 (boiling point: 198°C, manufactured by Maruzenseki Oil Co., Ltd.), etc.

When the photosensitive composition contains an organic dispersion medium, it is not particularly limited, but the proportion of the organic dispersion medium in the entire photosensitive composition is approximately 1 to 50% by mass, typically 3 to 30% by mass, for example, 5 to 20% by mass. It can be %.

<Other ingredients>

The photosensitive composition may contain various additional components as needed, in addition to the components described above, as long as they do not significantly impair the effect of the technology disclosed herein. As the additive component, one or two or more types can be appropriately selected and used from among conventionally known components. Examples of added components include, for example, inorganic fillers, photosensitizers, polymerization inhibitors, radical scavengers, antioxidants, ultraviolet absorbers, plasticizers, surfactants, leveling agents, thickeners, dispersants, anti-foaming agents, anti-gelling agents, and stabilizers. , preservatives, pigments, etc. Although not particularly limited, the proportion of the added component in the entire photosensitive composition may be approximately 5% by mass or less, for example, 3% by mass or less.

As mentioned above, the photosensitive composition disclosed herein contains the two types of components (1) and (2) above as a photopolymerization initiator. And, when the total photopolymerization initiator is 100% by mass, the proportion of (1) above accounts for 50% by mass or more. Thereby, in the development process, etching resistance (adhesion) and peelability can be balanced at a higher level. In other words, the etching resistance of the exposed portion can be improved and a long development margin time can be secured. As a result, the exposed portion can be properly fixed on the substrate after the development process, and the occurrence of abnormalities such as peeling or disconnection can be suppressed. Additionally, by improving the peelability of the conductive film, it is possible to appropriately remove the unexposed portion while suppressing the exposed portion from becoming too thick. In other words, fine line formation in the exposed portion can be improved. As a result, a space can be stably secured between neighboring wirings, and the occurrence of short circuit defects can be suppressed. In addition, according to the technology disclosed herein, in addition to these effects, even fine lines with a line width of 30 μm or less can be formed with good reproducibility. Additionally, yield can be improved.

<Use of photosensitive composition>

According to the photosensitive composition disclosed herein, a fine line with a line width finer than 30 μm can be stably formed at high resolution. Additionally, the occurrence of short circuit defects can be suppressed while reducing peeling or disconnection of the conductive layer. Therefore, the photosensitive composition disclosed herein can be suitably used for forming conductive layers in various electronic components such as inductance components, condenser components, and multilayer circuit boards, for example.

Electronic components may be of various mounting types, such as surface mounting type or through-hole mounting type. Electronic components may be of a laminated type, a wire-wound type, or a thin film type. Typical examples of inductance components include high-frequency filters, common-mode filters, inductors (coils) for high-frequency circuits, inductors (coils) for general circuits, high-frequency filters, choke coils, and transformers.

Additionally, a photosensitive composition in which the conductive powder contains core-shell particles of metal-ceramic can be suitably used for forming a conductive layer of a ceramic electronic component. In addition, in this specification, “ceramic electronic components” includes all electronic components having an amorphous ceramic substrate (glass ceramic substrate) or a crystalline (i.e. non-glass) ceramic substrate. As a typical example, a high-frequency filter with a ceramic substrate, a ceramic inductor (coil), a ceramic condenser, a low temperature fired multilayer ceramic substrate (Low Temperature Co-fired Ceramics Substrate: LTCC substrate), and a high temperature fired multilayer ceramic substrate (High Temperature Co-fired Ceramics) Substrate: HTCC substrate), etc.

Figure 1 is a cross-sectional view schematically showing the structure of the multilayer chip inductor 1. Additionally, the dimensional relationships (length, width, thickness, etc.) in FIG. 1 do not necessarily reflect the actual dimensional relationships. In addition, symbols X and Y in the drawing represent left and right directions and up and down directions, respectively. However, this is only for convenience of explanation.

The multilayer chip inductor 1 includes a main body 10 and external electrodes 20 provided on both side surfaces of the main body 10 in the left and right directions (X). The multilayer chip inductor 1 has sizes, for example, of 1608 shape (1.6mmХ0.8mm), 2520 shape (2.5mmХ2.0mm), etc.

The main body 10 has a structure in which a ceramic layer (dielectric layer) 12 and an internal electrode layer 14 are integrated. The ceramic layer 12 can constitute, for example, a coating of conductive powder and is made of the ceramic material described above. In the vertical direction Y, an internal electrode layer 14 is disposed between the ceramic layers 12. The internal electrode layer 14 is formed using the photosensitive composition described above. The internal electrode layers 14 adjacent in the vertical direction (Y) with the ceramic layer 12 in between are electrically connected through the via 16 provided in the ceramic layer 12. As a result, the internal electrode layer 14 is configured in a three-dimensional vortex shape (spiral shape). Both ends of the internal electrode layer 14 are respectively connected to the external electrode 20.

Such a multilayer chip inductor 1 can be manufactured, for example, by the following procedure.

That is, first, a paste containing raw ceramic materials, a binder resin, and an organic solvent is prepared, and this is supplied on a carrier sheet to form a ceramic green sheet. Next, this ceramic green sheet is rolled and cut to a desired size to obtain green sheets for forming a plurality of ceramic layers. Next, via holes are formed appropriately at predetermined positions on the plurality of green sheets for forming ceramic layers using a puncher or the like.

Next, using the above-described photosensitive composition, a conductive film with a predetermined coil pattern is formed at a predetermined position on a plurality of green sheets for forming a ceramic layer. As an example, the following steps: (Step S1: Forming process of film-like body) A process of forming a conductive film made of a dried body of the photosensitive composition by applying the photosensitive composition on a green sheet for forming a ceramic layer and drying it; (Step S2: Exposure process) A process of partially photocuring the conductive film by covering the conductive film with a photomask with a predetermined opening pattern and exposing the conductive film to light through the photomask; (Step S3: Development Process) A conductive film in an unbaked state can be formed by a manufacturing method including a process of etching the photocured conductive film to remove the unexposed portion.

In addition, when forming a conductive film using the photosensitive composition, conventionally known methods can be appropriately used. For example, in (Step S1), application of the photosensitive composition can be performed using various printing methods such as screen printing or a bar coater. Drying of the photosensitive composition may be performed at a temperature below the boiling point of the photopolymerizable compound and the photopolymerization initiator, typically 50 to 100°C. In (Step S2), for exposure, an exposure machine that emits light in a wavelength range of 10 to 500 nm, for example, an ultraviolet irradiation lamp such as a high-pressure mercury lamp, metal halide lamp, or xenon lamp, can be used. In (Step S3), an alkaline etching solution can typically be used for etching. For example, an aqueous solution containing sodium hydroxide, sodium carbonate, etc. can be used. The concentration of the alkaline aqueous solution may be adjusted to, for example, 0.01 to 0.5% by mass.

Next, (step S4: firing process), a plurality of green sheets for forming a ceramic layer on which an unsintered conductive film is formed are stacked and pressed. In this way, a laminate of unfired ceramic green sheets is produced. Next, the laminate of ceramic green sheets is fired at, for example, 600 to 1000°C. As a result, the ceramic green sheet is integrally sintered to form the main body portion 10 including the ceramic layer 12 and the internal electrode layer 14 made of a sintered body of the photosensitive composition. Then, an appropriate external electrode forming paste is applied to both ends of the main body 10 and fired, thereby forming the external electrode 20.

As described above, the multilayer chip inductor 1 can be manufactured.

Hereinafter, several embodiments according to the present invention will be described, but it is not intended to limit the present invention to those shown in these embodiments.

(Preparation of silver powder)

First, two types of commercially available silver powders (silver powders a and b) having different D ₅₀ particle sizes were prepared. In addition, silver powder a has a D ₅₀ particle size of 3.9 μm, and silver powder b has a D ₅₀ particle size of 2.8 μm. In addition, silver powder a and b both have a brightness L ^* of 50 to 80 in the L ^* a ^* b ^* color system based on Japanese Industrial Standards JIS Z 8781: 2013.

Additionally, silver powder c was prepared using silver powder a. Specifically, first, zirconium butoxide was added to methanol to prepare a coating liquid. Next, silver powder a was added to this coating liquid and stirred for 1 hour. Next, solid content was recovered from the coating liquid and dried at 100°C. As a result, silver powder (core-shell particles of silver-zirnia) surface-coated with zirconium butoxide in an amount of 0.5 parts by mass in terms of zirconium oxide (ZrO ₂ ) relative to 100 parts by mass of silver powder was obtained. In this way, silver powder c was prepared.

(Preparation of photopolymerization initiator)

Next, four types of commercially available photopolymerization initiators (initiators a to d) shown below were prepared. In addition, initiators a and b are α-aminoalkylphenone-based photopolymerization initiators, and initiators c and d are acyl phosphine oxide-based photopolymerization initiators.

Initiator a: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1

Initiator b: 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone

Initiator c: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

Initiator d: Bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide

(Preparation of photosensitive composition)

First, the urethane acrylate monomer as a photopolymerizable compound, the organic binder, and the photopolymerization initiator were weighed so as to have the content ratios shown in Table 1 and dissolved in an organic dispersion medium to prepare a vehicle. Then, photosensitive compositions (Examples 1 to 7 and Comparative Examples 1 to 6) were prepared by mixing the prepared silver powder and the prepared vehicle at a mass ratio of 77:23. In addition, the mass ratio shown in Table 1 is when the total of the photosensitive composition is 100 mass%, and if the total mass ratio shown in Table 1 is less than 100 mass%, other added components (for example, polymerization This means that it contains trace amounts of inhibitors, sensitizers, anti-gelling agents, and ultraviolet absorbers.

(Production of wiring pattern)

First, using a stainless steel screen, the prepared photosensitive composition was applied onto commercially available ceramic green sheets. Next, this was dried at 60°C for 15 minutes, and a conductive film was formed on the green sheet (film-like body forming step). Next, a photomask was applied from above the conductive film. At this time, as a photomask, a spiral pattern with a line width of 25 μm and a space between adjacent lines of 25 μm (L/S = 25 μm/25 μm) was used. With this photomask covered, light was irradiated with an intensity of 2500 mJ/cm ² using an exposure machine, and the exposed portion was cured (exposure process). After exposure, a 0.1% by mass alkaline Na ₂ CO ₃ aqueous solution was sprayed on the surface of the ceramic green green sheet until the break point (BP) was reached (development process). Here, BP was set as the time until the unexposed part was developed with an alkaline etching solution of 0.1% by mass and it could be visually confirmed that the unexposed part had disappeared. After removing the unexposed portion in this way, it was washed with pure water and dried at room temperature. Then, this was fired at 700°C (calcination process). In this way, a conductive layer with a wiring pattern in which swirl-shaped wiring was arranged was formed on the ceramic green sheet.

(Evaluation of wiring pattern)

In the wiring pattern produced above, peeling, line width, and development margin were evaluated, and a comprehensive evaluation was performed based on these evaluations.

·Evaluation of peeling:

The wiring pattern was observed with an electron microscope to evaluate peeling. In addition, the observation image was taken at a magnification of 200 times. Then, the presence or absence of peeling and disconnection was confirmed in the obtained observation image. The results are shown in the “Evaluation of Peeling” column in Table 1. The notation in the relevant column is as follows.

「○」: No peeling

「△」: Partial peeling (no disconnection)

「Х」: There is peeling and disconnection.

·Evaluation of line width:

From the observation image, the line width of the wiring pattern was measured. In addition, the line width was measured in multiple fields of view, and the arithmetic average value was taken as the line width (μm). The results are shown in the “Line Width” column of Table 1. In addition, the notation in the evaluation column is as follows.

「○」: 20~30μm (within target value range)

「Х」: 30μm or more

In addition, Figure 2 shows the relationship between the content ratio of the initiator c and the line width of the wiring pattern in the evaluation results of Comparative Examples 1 to 3 and Examples 1 to 4.

·Evaluation of phenomenon margin:

In the above exposure process, an alkaline etching solution was sprayed for an additional 10 seconds (B.P. + 10 seconds) beyond the break point. Then, the conductive film after the exposure process was observed with an electron microscope as described above, and the development margin was evaluated from the obtained observation image. The results are shown in the “Evaluation of development margin” column in Table 1. The notation in the relevant column is as follows.

「○」: The shape of the conductive film is maintained.

「Х」: The shape of the conductive film is not maintained.

·Comprehensive evaluation:

「○」: In each evaluation of peeling, line width, and development margin described above, there is no △ or Х (all are ○)

「△」: In each evaluation of peeling, line width, and development margin described above, there is one △, and the rest are ○.

「Х」: In each evaluation of peeling, line width, and development margin described above, Х is 1 or more.

Comparative Examples 1 and 2 are test examples using only the initiator a. As shown in Table 1, in Comparative Example 1, a development margin of more than 10 seconds could be secured, but there was a large variation in line width in the conductive pattern, and it was confirmed that the line width was starved in some places. As a result, the line width became too much larger than the target value, making it difficult to form a stable fine line. Additionally, in Comparative Example 2, where the content ratio of initiator a was reduced compared to Comparative Example 1, a sufficient development margin could not be secured. Comparative Example 4 is a test example using only initiator c. As shown in Table 1, in Comparative Example 4, peeling and disconnection were confirmed in the conductive pattern, making it difficult to form fine lines.

Comparative Example 3 and Examples 1 to 4 are test examples in which initiators a and c were used together. As shown in Table 1 and Figure 2, in Comparative Example 3, where the content of initiator c was small, the effect of addition of initiator c was not sufficiently expressed, and it was difficult to form a stable fine line like Comparative Example 1. On the other hand, in Examples 1 to 4 where the content of the initiator c was 50% by mass or more of the total photopolymerization initiator, the development margin was sufficiently secured, and a fine line with the desired line width was stably formed. Additionally, by increasing the content ratio of the initiator c, the thin wire formation property was further improved. In particular, in Examples 1 to 3 where the mass ratio of initiator c:initiator a was 50:50 to 85:15, the etching resistance of the exposed portion was improved, and peeling of the conductive layer was better suppressed.

Example 5 is a test example in which initiator b, which is the same α-aminoalkylphenone family, was used instead of initiator a. As shown in Table 1, in Example 5, as in Examples 1 to 4, a sufficient development margin was secured and the formation of a stable fine line was realized. In other words, even when initiator b was used instead of initiator a, the effect of the technology disclosed here was exhibited.

Comparative Examples 5 and 6 are test examples in which the acyl phosphine oxide-based initiator d was used instead of the initiator c. As shown in Table 1, in Comparative Examples 5 and 6, unlike Examples 1 to 4, the development margin was insufficient and/or formation of a stable fine line was difficult. In other words, when initiator d was used instead of initiator c, the effect of the technology disclosed here was not exhibited.

Examples 6 and 7 are test examples in which silver powder c was used instead of silver powder a and b. As shown in Table 1, in Examples 6 and 7, as in Examples 1 to 4, a sufficient development margin was secured and the formation of a stable fine line was realized. Additionally, compared to the case where silver powder a and b were used, the effect of the technology disclosed here was exhibited at a higher level, and the fine wire formation property was further improved.

As described above, as a photopolymerization initiator, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (initiator c) and α-aminoalkylphenone (initiator a, b) are used in combination, and 2,4 By including 6-trimethylbenzoyl-diphenyl-phosphine oxide in a proportion of 50% by mass or more of the total photopolymerization initiator, it was possible to secure a long development margin time in the development process. Additionally, fine line formation in the exposed portion could be improved. As a result, even fine lines with a line width of 30 μm or less could be formed with good reproducibility. In addition, the occurrence of abnormalities such as short circuit defects, peeling, and disconnection was suppressed, and the yield was improved. These results demonstrate the significance of the technology disclosed herein.

Although the present invention has been described in detail above, these are merely examples, and various changes can be made to the present invention without departing from its main scope.

1 stacked chip inductor
10 Main body
12 Ceramic layer
14 Internal electrode layer
20 external electrode

Claims (12)

A photosensitive composition used to produce a conductive layer containing wiring with a line width of 30 μm or less,
Contains conductive powder, a photopolymerizable compound, a photopolymerization initiator, and an organic binder (except for an organic binder having a photoreactive (meth)acryloyl group in the molecule),
The photopolymerization initiator is,
At least two of the following ingredients:
(1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide;
(2) α-aminoalkylphenones;
A photosensitive composition comprising: (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide accounts for 50% by mass or more when the total of the photopolymerization initiators is 100% by mass. A photosensitive composition used to produce a conductive layer containing wiring with a line width of 30 μm or less,
Contains conductive powder, a photopolymerizable compound, and a photopolymerization initiator,
The photopolymerization initiator is,
At least two of the following ingredients:
(1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide;
(2) α-aminoalkylphenones;
and when the total of the photopolymerization initiators is 100% by mass, the 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (1) above accounts for 50% by mass or more, and (1) 2 , the mass ratio of 4,6-trimethylbenzoyl-diphenyl-phosphine oxide and the (2) α-aminoalkylphenones is 50:50 to 85:15, and the ratio of the photopolymerization initiator in the entire photosensitive composition is A photosensitive composition of 0.3% by mass or less. In claim 1 or claim 2,
A photosensitive composition wherein the mass ratio of (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and (2) α-aminoalkylphenone is 50:50 to 90:10. In claim 1 or claim 2,
A photosensitive composition wherein the mass ratio of (1) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and (2) α-aminoalkylphenone is 50:50 to 85:15. In claim 1 or claim 2,
A photosensitive composition wherein the photopolymerizable compound includes a photopolymerizable compound having a urethane bond. In claim 1 or claim 2,
A photosensitive composition in which the conductive powder contains silver-based particles. In claim 1 or claim 2,
A photosensitive composition, wherein the conductive powder includes a core portion containing a metal material, a core shell particle that covers at least a portion of the surface of the core portion, and has a covering portion containing a ceramic material. In claim 1 or claim 2,
A photosensitive composition wherein the brightness L ^* of the conductive powder is 50 or more in the L ^* a ^* b ^* colorimetric system based on Japanese Industrial Standards JIS Z 8781:2013. In claim 1 or claim 2,
A photosensitive composition further comprising an organic solvent having a boiling point of 150°C or higher and 250°C or lower. green sheet,
A conductive film disposed on the green sheet and made of a dried body of the photosensitive composition of claim 1 or claim 2.
A complex comprising: An electronic component comprising a conductive layer made of a sintered body of the photosensitive composition of claim 1 or 2. A method of manufacturing an electronic component, comprising the step of applying the photosensitive composition of claim 1 or 2 on a substrate, exposing and developing, and then baking to form a conductive layer made of a sintered body of the photosensitive composition.