Photosensitive conductive paste, method for producing laminated electronic component, and laminated electronic component

Abstract

To provide a photosensitive conductive paste, a method for producing a laminated electronic component, and a laminated electronic component, achieving controlled shrinkage behavior during a firing process.SOLUTION: A photosensitive conductive paste includes: a conductive powder; an alkali-soluble polymer; a photosensitive monomer; a photopolymerization initiator; a solvent; and an organic flame retardant. In another form, the photosensitive conductive paste includes: a conductive powder; an organic component; and a solvent, and also includes a cellulose derivative as the alkali-soluble polymer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a photosensitive conductive paste, a method for manufacturing a laminated electronic component, and a laminated electronic component.

Background Art

[0002] In recent years, laminated electronic components such as laminated ceramic circuit boards have been manufactured by forming internal electrodes using a photosensitive conductive paste. The internal electrodes are formed by sintering the conductive powder contained in the photosensitive conductive paste after patterning the photosensitive conductive paste and then firing. Examples of the photosensitive conductive paste used for laminated electronic components include those disclosed in JP-A-2002-169274 (Patent Document 1) and JP-A-2007-18884 (Patent Document 2).

[0003] JP-A-2002-169274 discloses a photosensitive conductive paste containing, as main components, 40 to 80 wt% of a conductive powder, 3 to 20 wt% of a photopolymerizable compound, 10 wt% or less of a photoinitiator, and 0.3 to 2.5 wt% of one or more non-conductive metal oxides. The non-conductive metal oxides are generally called "co-materials". In JP-A-2002-169274, it is stated that the firing shrinkage of the internal electrodes can be reduced because of the inclusion of co-materials.

[0004] JP-A-2007-18884 discloses a photosensitive conductive paste containing a first conductive powder having an average particle size of 5 μm or less obtained by an atomization method and a second conductive powder having an average particle size in the range of 0.2 to 2.0 μm obtained by a wet reduction method in a weight ratio within the range of 20 / 80 ≤ (first conductive powder / second conductive powder) ≤ 80 / 20. In JP-A-2007-18884, it is stated that the firing shrinkage of the internal electrodes can be reduced because of the inclusion of the first conductive powder having a relatively large average particle size.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2002-169274 Patent Document 2 Japanese Patent Application Laid-Open No. 2007-18884 Summary of the Invention Problems to be Solved by the Invention

[0006] However, it has been found that delamination may occur even if the firing shrinkage of the internal electrodes is reduced, when the shrinkage of the photosensitive conductive paste during firing does not correspond to the shrinkage of the base material.

[0007] Therefore, an object of the present disclosure is to provide a photosensitive conductive paste in which the shrinkage behavior during firing is controlled. Further, an object of the present disclosure is to provide a method for manufacturing a multilayer electronic component and a multilayer electronic component using this photosensitive conductive paste. Means for Solving the Problems

[0008] In order to solve the above problems, a photosensitive conductive paste according to one aspect of the present disclosure includes a conductive powder, an organic component, and a solvent, The organic component includes an alkali-soluble polymer, a photosensitive monomer, a photopolymerization initiator, and an organic flame retardant.

[0009] In order to solve the above problems, a photosensitive conductive paste according to another aspect of the present disclosure includes a conductive powder, an organic component, and a solvent, The organic component includes an alkali-soluble polymer, a photosensitive monomer, and a photopolymerization initiator, The alkali-soluble polymer includes a cellulose derivative.

[0010] According to the above aspect, since the shrinkage behavior of the photosensitive conductive paste during firing is controlled, when this is used as the internal electrode of a multilayer electronic component, the deviation from the shrinkage behavior of the green body material during firing is reduced, and delamination is suppressed. In addition, since a co-material is not an essential component and an increase in the large particle size of the conductive powder is not required, the resolution during photolithographic patterning is improved, and the electrical resistance of the formed internal electrode can be reduced.

Advantages of the Invention

[0011] According to the photosensitive conductive paste according to the present disclosure, the shrinkage behavior of the photosensitive conductive paste during firing is controlled.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0013] Hereinafter, a photosensitive conductive paste, a method for manufacturing a multilayer electronic component, and a multilayer electronic component, which are an aspect of the present disclosure, will be described in detail with reference to the illustrated embodiments. Note that the drawings include some schematic ones and may not reflect actual dimensions and ratios.

[0014] [First Embodiment] (Overall Configuration of Multilayer Electronic Component) FIG. 1 is a perspective view schematically showing a multilayer electronic component. FIG. 2 is an exploded perspective view schematically showing a multilayer electronic component. In FIG. 1, the green body is drawn transparently so that the structure can be easily understood, but it may be translucent or opaque. In FIG. 1, the description of the coil is omitted so that the structure can be easily understood. In FIG. 2, the description of the external electrode is omitted for ease of viewing.

[0015] Hereinafter, a multilayer coil component will be described as an example of the multilayer electronic component. However, the multilayer electronic component of the present disclosure is not limited to the multilayer coil component and can be applied to various multilayer electronic components such as multilayer capacitor components and multilayer LC composite components.

[0016] As shown in FIGS. 1 and 2, the multilayer electronic component 10 includes a body 4, a coil 5 provided in the body 4, and a first external electrode 6a and a second external electrode 6b provided on the body 4. The coil 5 corresponds to the "internal electrode" described in the claims.

[0017] The shape of the body 4 is not particularly limited, but in this embodiment, it is substantially rectangular parallelepiped. The outer surface of the body 4 includes a first end face 41, a second end face 42 facing the first end face 41, a first side face 43 connecting the first end face 41 and the second end face 42, a second side face 44 facing the first side face 43, a bottom face 45 connecting the first end face 41, the second end face 42, the first side face 43, and the second side face 44, and a top face 46 facing the bottom face 45 and connecting to the first end face 41, the second end face 42, the first side face 43, and the second side face 44. The direction from the first end face 41 to the second end face 42 is defined as the X direction, the direction from the first side face 43 to the second side face 44 is defined as the Y direction, and the direction from the bottom face 45 to the top face 46 is defined as the Z direction. In this specification, the Z direction may sometimes be referred to as the upper side.

[0018] The base body 4 is composed of a plurality of insulating layers 40 laminated. The insulating material of the insulating layer 40 is not particularly limited. For example, it includes borosilicate glass and inorganic fillers. The inorganic fillers are, for example, glass powder and ceramic aggregates such as alumina. The lamination direction of the insulating layer 40 is parallel to the Z direction. That is, the insulating layer 40 is in a layer shape spreading in the XY plane. In the insulating layer 40 located between adjacent coil wirings 2 among the plurality of coil wirings 2 described later, via holes 3 are provided at the positions where the adjacent coil wirings 2 are connected. The via holes 3 penetrate the insulating layer 40 in the thickness direction (Z direction). In the present application, "parallel" is not limited to a strict parallel relationship, and includes a substantial parallel relationship considering the range of realistic variations. Note that in the base body 4, the interfaces between the plurality of insulating layers 40 may not be clear due to firing or the like.

[0019] The first external electrode 6a and the second external electrode 6b are composed of a conductive material such as Ag, Cu, Au, or an alloy having these as main components. In this embodiment, the first external electrode 6a is continuously provided on the entire surface of the first end face 41 of the base body 4, the end portion on the first end face 41 side of the first side face 43, the end portion on the first end face 41 side of the second side face 44, the end portion on the first end face 41 side of the bottom face 45, and the end portion on the first end face 41 side of the top face 46. Also, the second external electrode 6b is continuously provided on the entire surface of the second end face 42 of the base body 4, the end portion on the second end face 42 side of the first side face 43, the end portion on the second end face 42 side of the second side face 44, the end portion on the second end face 42 side of the bottom face 45, and the end portion on the second end face 42 side of the top face 46. In short, each of the first external electrode 6a and the second external electrode 6b is a five-sided electrode. However, it is not limited to this. For example, the first external electrode 6a may be an L-shaped electrode continuously provided on a part of the first end face 41 and a part of the bottom face 45. Similarly, the second external electrode 6b may be an L-shaped electrode continuously provided on a part of the second end face 42 and a part of the bottom face 45.

[0020] The coil 5 is a sintered body of a photosensitive conductive paste containing conductive powder such as Ag, Cu, etc. The coil 5 is spirally wound along the stacking direction of the insulating layer 40. The first end 5a of the coil 5 is exposed from the first end face 41 of the base body 4 and is connected to the first external electrode 6a. The second end 5b of the coil 5 is exposed from the second end face 42 of the base body 4 and is connected to the second external electrode 6b.

[0021] When viewed from the axial direction, the coil 5 is formed in a rectangular shape, but is not limited to this shape. The shape of the coil 5 may be, for example, circular, elliptical, rectangular, or other polygons. Also, the axial direction of the coil 5 is parallel to the Z direction and is wound along the axial direction. The axis of the coil 5 means the central axis of the spiral shape of the coil 5.

[0022] The coil 5 has a plurality of coil wirings 2 stacked along the axial direction and via wirings (not shown) that extend along the axial direction and connect the coil wirings 2 adjacent to each other in the axial direction. The plurality of coil wirings 2 are each wound along a plane, arranged side by side in the axial direction, and form a spiral while being electrically connected in series.

[0023] The coil wiring 2 is formed by being wound on the main surface (XY plane) of the insulating layer 40 orthogonal to the axial direction. The number of turns of the coil wiring 2 is less than one turn, but may be one turn or more. The via wiring is provided in the via hole 3 of the insulating layer 40 and penetrates the insulating layer 40 in the thickness direction (Z direction). And the coil wirings 2 adjacent to each other in the stacking direction are electrically connected in series via the via wiring.

[0024] In such a multilayer electronic component 10, a plurality of insulating layers 40 and a patterning layer of the photosensitive conductive paste are alternately stacked in multiple layers, and each of the plurality of insulating layers 40 and the plurality of patterning layers of the photosensitive conductive paste is sintered. Thereby, the base body 4 is formed from the plurality of insulating layers 40, and the coil 5 is formed from the plurality of patterning layers of the photosensitive conductive paste.

[0025] (Detailed Configuration of Photosensitive Conductive Paste) Next, the detailed configuration of the photosensitive conductive paste used for forming the coil 5 will be described. Hereinafter, the photosensitive conductive paste used for forming the coil 5 of the multilayer electronic component 10, which is a multilayer coil component, will be described. However, the photosensitive conductive paste of the present disclosure is not limited thereto, and can be used for forming internal electrodes of various multilayer electronic components such as multilayer capacitor components and multilayer LC composite components. For example, in the case of a multilayer capacitor component, the photosensitive conductive paste of the present disclosure can be used for forming capacitor electrodes.

[0026] The photosensitive conductive paste contains a conductive powder, an organic component, and a solvent.

[0027] <Conductive powder> The conductive powder is sintered by firing to become the conductor of the coil 5. The type of the conductive powder is not particularly limited, but it may be silver (Ag) or copper (Cu) in order to reduce the electrical resistance of the formed coil 5. The content of the conductive powder with respect to the photosensitive conductive paste may be 65% by weight or more and 90% by weight or less. From the viewpoint of suppressing the shrinkage of the photosensitive conductive paste after firing, the content of the conductive powder with respect to the photosensitive conductive paste may be 70% by weight or more and 85% by weight or less.

[0028] The average particle diameter D50 (median diameter) of the conductive powder may be 0.5 μm or more and 5.0 μm or less from the viewpoint of forming a fine pattern of the coil 5. The average particle diameter D50 is the 50% particle diameter in the volume-based particle size distribution measured by a laser diffraction type particle size distribution measuring device (for example, MT3000 manufactured by Microtrac Bell).

[0029] The conductive powder may be silver (Ag) powder. The average particle diameter D50 of the Ag powder may also be 0.5 μm or more and 5.0 μm or less. In particular, the conductive powder may be atomized Ag powder manufactured by an atomization method. The atomized Ag powder has a larger crystallite diameter of the conductive powder and less organic impurities than the Ag powder manufactured by a wet reduction method. Therefore, the electrical resistance of the formed coil 5 is further reduced.

[0030] <Organic component> The organic component contains at least an alkali-soluble polymer, a photosensitive monomer, a photopolymerization initiator, and an organic flame retardant. The content of the organic component may be 5% by weight or more, and may be 8% by weight or more, based on the photosensitive conductive paste. The content of the organic component may be 20% by weight or less, and may be 15% by weight or less, based on the photosensitive conductive paste.

[0031] The organic component decomposes by heating. This weight loss (in this case, synonymous with volume reduction) of the organic component causes the coil 5 to contract. However, if the shrinkage behavior of the photosensitive conductive paste during firing corresponds to the shrinkage behavior of the base material, delamination, which is a structural defect that may occur between the resulting coil 5 and the base body 4, can be suppressed.

[0032] The base material typically contains borosilicate glass, and its softening point is usually above 700 °C. When the glass component softens by heating above 700 °C, the sintering of the base material proceeds rapidly and it is sintered. That is, the base material exhibits a shrinkage behavior in which the shrinkage is small until the glass component softens, and then rapidly shrinks after the glass component softens.

[0033] The photosensitive conductive paste according to the present disclosure contains an organic flame retardant. Therefore, the decomposition rate of the organic component is reduced, and the shrinkage of the photosensitive conductive paste proceeds gently during firing. As described above, the base material also has a small shrinkage until the glass component softens. That is, the shrinkage of both the photosensitive conductive paste and the base material at the beginning of firing is small, and the shrinkage behaviors of both correspond.

[0034] On the one hand, like other organic components, organic flame retardants also decompose upon heating. Therefore, when the decomposition temperature of the organic components is reached, the role of the organic flame retardants ends, and the organic components decompose rapidly. That is, in the latter half of the firing stage, the decomposition of the organic components proceeds rapidly, causing shrinkage of the photosensitive conductive paste. Thus, even in the latter half of the firing stage, the shrinkage behavior of the base material and the shrinkage behavior of the photosensitive conductive paste correspond to each other. Thereby, suppression of delamination can be expected.

[0035] Organic flame retardants do not contain metal atoms. Therefore, the influence on the properties of the resulting coil 5 (especially the electrical resistance) is small. If the flame retardant contains metal atoms, it may remain in the coil 5 as a metal oxide after firing. Metal oxides are usually non-conductive and can increase the electrical resistance of the coil 5, similar to the co-material.

[0036] The cured product of the organic component (hereinafter referred to as the "first cured product") used in the photosensitive conductive paste according to the present disclosure may satisfy the following conditions A and B with respect to the thermal decomposability in an oxygen atmosphere. (Condition A) In thermogravimetric measurement, the weight loss rate at 300 °C is less than 50%. (Condition B) In thermogravimetric measurement, the weight loss rate at 700 °C is 100%.

[0037] Condition A indicates that the degree of thermal decomposition of the cured product is small up to 300 °C. That is, it means that the shrinkage rate of the photosensitive conductive paste up to 300 °C is small. At temperatures up to 300 °C, as described above, the shrinkage of the base material is also small. That is, up to 300 °C, the shrinkage of both the photosensitive conductive paste and the base material is small, and the shrinkage behaviors of both correspond to each other. The weight loss rate of the cured product at 300 °C (hereinafter sometimes referred to as ΔTG) may be less than 40%, may be less than 35%, or may be less than 30%.

[0038] However, it is desirable that the thermal decomposition of the organic components contained in the photosensitive conductive paste be completed before the glass component of the base material starts to soften. If the organic components remain when the glass component of the base material starts to soften, the decomposed and gasified organic components will be trapped by the molten glass component. The gaseous organic components remaining inside the multilayer electronic component 10 can also contribute to delamination.

[0039] Condition B indicates that the decomposition of the first cured product is completed by 700°C. When the temperature exceeds 700°C, as described above, the glass component of the base material starts to soften. By completing the decomposition of the first cured product by 700°C, the trapping of the gasified organic components as described above is suppressed. The first cured product may have a weight loss rate of 100% at 600°C.

[0040] By satisfying both of the above conditions A and B, it can be said that the organic components contained in the photosensitive conductive paste decompose gently until 300°C and complete the decomposition (the weight loss rate becomes 100%) between exceeding 300°C and reaching 700°C. That is, since the shrinkage behavior of the base material during firing and the shrinkage behavior of the photosensitive conductive paste correspond to each other, suppression of delamination can be expected.

[0041] The first cured product is obtained by mixing each organic component at the ratio in which it is blended in the photosensitive conductive paste and then curing. The first cured product may be obtained by curing a first mixture obtained by mixing a photosensitive monomer, an alkali-soluble polymer, a photopolymerization initiator, and an organic flame retardant at the ratio in which they are blended in the photosensitive conductive paste. This is because the blending amounts of other organic components (typically, additives described later) are small and their influence on ΔTG is small.

[0042] The content of the photosensitive monomer in the first mixture is, for example, 30% by weight or more and 60% by weight or less. The content of the alkali-soluble polymer in the first mixture is, for example, 30% by weight or more and 60% by weight or less. The content of the photoinitiator in the first mixture is, for example, 3% by weight or more and 10% by weight or less. The content of the organic flame retardant in the first mixture is, for example, 1% by weight or more and 30% by weight or less.

[0043] The thermal decomposability of the first cured product in an oxygen atmosphere may further satisfy the following condition C. (Condition C) In thermogravimetric measurement, the change in the weight loss rate in the range of 300 °C or more and 400 °C or less is 70% or less.

[0044] Condition C indicates that the weight of the first cured product decreases with a certain gentleness even after exceeding 300 °C. This means that the shrinkage of the photosensitive conductive paste proceeds gently until the degreasing is completed. This shrinkage behavior corresponds more closely to the shrinkage behavior of the green body material during firing, so further suppression of delamination can be expected.

[0045] The change in the weight loss rate in the range of 300 °C or more and 400 °C or less refers to the weight loss rate ΔTG of the first cured product at 300 °C 300 and the weight loss rate ΔTG of the first cured product at 400 °C 400 and the difference (|ΔTG 300 -ΔTG 300 |).

[0046] ≪Alkali-soluble polymer≫ The alkali-soluble polymer is neutralized with a basic compound and solubilized. The alkali-soluble polymer is removed together with the uncured photosensitive monomer and conductive powder, etc. during the development process using an alkaline developer, for example. On the other hand, when the photosensitive monomer polymerizes by active energy rays, the alkali-soluble polymer present in the vicinity thereof forms a film together with the polymer of the photosensitive monomer and forms, for example, a part of the internal electrode pattern. Thereby, the adhesion of the internal electrode pattern to the insulating layer can be improved.

[0047] The content of the alkali-soluble polymer may be 30% by weight or more, and may be 35% by weight or more, based on the organic component. The content of the alkali-soluble polymer may be 60% by weight or less, and may be 55% by weight or less, based on the organic component.

[0048] The photosensitive conductive paste may contain one type of alkali-soluble polymer, or may contain two or more types of alkali-soluble polymers.

[0049] The alkali-soluble polymer has at least one acid group in the side chain. As the acid group, typically, a carboxy group can be mentioned. The alkali-soluble polymer contains, as the main chain, for example, a polymer chain having at least one of a carbon-carbon bond, an ether bond, a urea bond, an ester bond, and a urethane bond. From the viewpoint of transparency, the main chain of the alkali-soluble polymer may contain a polymer chain having a carbon-carbon bond.

[0050] The alkali-soluble polymer having at least one carboxy group in the side chain and containing a polymer chain having a carbon-carbon bond as the main chain can be obtained, for example, by copolymerization of an unsaturated carboxylic acid and an ethylenically unsaturated compound. As the alkali-soluble polymer, typically, a carboxy group-containing acrylic polymer can be mentioned.

[0051] Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, vinylacetic acid, and dimers and anhydrides thereof. These can be used alone or in combination of two or more.

[0052] Examples of ethylenically unsaturated compounds include acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and isobornyl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and isobornyl methacrylate; fumaric esters such as monoethyl fumarate; and styrene. These may be used alone or in combination of two or more.

[0053] The carboxy group of the alkali-soluble polymer may be introduced after the main chain is formed. The carboxy group of the alkali-soluble polymer may be introduced, for example, by having an epoxy group in the side chain and reacting an unsaturated monocarboxylic acid with a compound having the above polymer chain, and then further reacting with a saturated or unsaturated polycarboxylic acid anhydride.

[0054] The alkali-soluble polymer may have an unsaturated bond. The unsaturated bond of the alkali-soluble polymer may be introduced, for example, by adding a monomer having a polymerizable functional group (typically, an epoxy group) that is reactive with a carboxyl group in the side chain.

[0055] The weight average molecular weight (Mw) of the alkali-soluble polymer may be 5,000 or more and 50,000 or less. The acid value of the alkali-soluble polymer may be 30 mgKOH / g or more and 150 mgKOH / g or less.

[0056] ≪Photosensitive Monomer≫ The photosensitive monomer reacts with a photoinitiator to generate monomer radicals. The monomer radicals polymerize to form a polymer. The content of the photosensitive monomer may be 30% by weight or more, and may be 35% by weight or more, based on the organic components. The content of the photosensitive monomer may be 60% by weight or less, and may be 50% by weight or less, based on the organic components.

[0057] The photosensitive conductive paste may contain one type of photosensitive monomer or may contain two or more types of photosensitive monomers.

[0058] The photosensitive monomer is not limited as long as it has at least one reactive group that undergoes a radical reaction. Examples of the radical reactive group include at least one selected from the group consisting of an acrylamide group, an acryloyl group, a methacryloyl group, an allyl group, a vinyl group, a styryl group, and a mercapto group. The photosensitive monomer may have at least one (meth)acryloyl group as the radical reactive group. The "(meth)acryloyl group" represents an acryloyl group and / or a methacryloyl group.

[0059] (Meth)acrylic monomers having a (meth)acryloyl group include monofunctional (meth)acrylate monomers such as stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, caprolactone (meth)acrylate, ethoxylated nonylphenol (meth)acrylate; difunctional (meth)acrylate monomers such as tripropylene glycol di(meth)acrylate, EO-modified diacrylate of isocyanuric acid, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate; trifunctional (meth)acrylate monomers such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, propoxylated glyceryl tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, caprolactone-modified tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, hexanediol tri(meth)acrylate, tripropylene glycol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate; tetrafunctional (meth)acrylate monomers such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, tripentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate;Pentafunctional (meth)acrylate monomers such as dipentaerythritol penta(meth)acrylate, tripentaerythritol penta(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate; hexafunctional (meth)acrylate monomers such as dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate; (meth)acrylate monomers having seven or more functional groups such as tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, etc. These may be used alone or in combination of two or more.;

[0060] The photosensitive monomer may be a (meth)acrylate monomer having three or more functional groups, may be a (meth)acrylate monomer having four or more functional groups, or may be a (meth)acrylate monomer having five or more functional groups. The photosensitive monomer may be dipentaerythritol monohydroxy penta(meth)acrylate.

[0061] ≪Photoinitiator≫ The photoinitiator generates highly reactive radicals upon exposure to active energy rays. The radicals add to the photosensitive monomer to initiate the reaction of the photosensitive monomer. The radicals are generated in a chain reaction, and eventually a polymer derived from the photosensitive monomer is formed. The content of the photoinitiator may be 3% by weight or more, or may be 5% by weight or more with respect to the organic components. The content of the photoinitiator may be 10% by weight or less, or may be 8% by weight or less with respect to the organic components.

[0062] Examples of the photoinitiator include at least one selected from the group consisting of benzoin or benzoin ether compounds, alkylphenone compounds, benzophenone compounds, oxime ester compounds, acylphosphine oxide compounds, and α-ketoester compounds. The photoinitiator may be an alkylphenone compound, may be an α-aminoalkylphenone compound, and may be 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one.

[0063] ≪Organic Flame Retardant≫ The organic flame retardant is a flame retardant that does not contain a metal atom. By the organic flame retardant, the shrinkage behavior of the photosensitive conductive paste during firing is controlled, and delamination between the base body 4 and the coil 5 is suppressed.

[0064] The content of the organic flame retardant may be 3% by weight or more, and may be 5% by weight or more with respect to the organic component. The content of the organic flame retardant may be 20% by weight or less, may be 15% by weight or less, and may be 10% by weight or less with respect to the organic component.

[0065] The organic flame retardant may be at least one selected from the group consisting of phosphate ester compounds, thioether compounds, nitrogen-containing aromatic compounds, brominated hydrocarbon compounds, and chlorinated hydrocarbon compounds. The organic flame retardant may be at least one of a thioether compound and a chlorinated hydrocarbon compound.

[0066] Examples of phosphate ester compounds include phosphate esters such as triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), trimethyl phosphate (TMP), triethyl phosphate (TEP), cresyl diphenyl phosphate (CDP), cresyl di-2,6-xylenyl phosphate, triallyl phosphate (IPPP); aromatic condensed phosphate esters such as 1,3-phenylene bis(diphenyl phosphate), 1,3-phenylene bis(dixylenyl) phosphate, resorcinol bis(diphenyl) phosphate, bisphenol A bis(diphenyl phosphate); halogen-containing phosphate esters such as tris(dichloropropyl) phosphate, tris(β-chloropropyl) phosphate, tris(chloroethyl) phosphate; and halogen-containing condensed phosphate esters such as 2,2-bis(chloromethyl)trimethylene bis(bis(2-chloroethyl) phosphate), polyoxyalkylene bisdichloroalkyl phosphate. These can be used alone or in combination of two or more.

[0067] Examples of thioether compounds include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol - tetrakis(3 - laurylthiopropionate), pentaerythritol - tetrakis(3 - dodecylthiopropionate), pentaerythritol - tetrakis(3 - octadecylthiopropionate), pentaerythritol tetrakis(3 - myristylthiopropionate), pentaerythritol - tetrakis(3 - stearylthiopropionate). These can be used alone or in combination of two or more.

[0068] Examples of the nitrogen-containing aromatic compounds include melamine compounds, triazine compounds, and guanidine compounds. Specific examples of the nitrogen-containing aromatic compounds include trichlorotriazine, piperazine, melamine cyanurate, and reaction products of melamine-based compounds and polyphosphoric acid. These may be used alone or in combination of two or more.

[0069] Examples of the brominated hydrocarbon compounds include hexabromocyclododecane, tetrabromocyclooctane, hexabromobenzene, pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, tetrabromobisphenol A (TBBA), TBBA-epoxy oligomer, TBBA-polycarbonate oligomer, TBBA-bis(dibromopropyl ether), TBBA-bis(aryl ether), 1,2-bis(2,4,6-tribromophenoxy)ethane, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, 2,6-dibromophenol, 2,4-dibromophenol, brominated polystyrene, and ethylene bis(tetrabromophthalimide). These may be used alone or in combination of two or more.

[0070] Examples of the chlorinated hydrocarbon compounds include chlorinated paraffin, 1,6,7,8,9,14,15,16,17,17,18,18-dodecachloropentacyclo[12.2.1.16,9.02,13.05,10]octadeca-7,15-diene, and chlorinated polyethylene. These may be used alone or in combination of two or more.

[0071] The organic component may further contain additives such as a sensitizer, an antifoaming agent, an anti-settling agent, and a dispersant.

[0072] <Solvent> The solvent is not particularly limited. For example, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoethylhexyl ether, propylene glycol monobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, propylene glycol monophenyl ether, ethyl acetate, butyl acetate, pentyl acetate, hexyl acetate, cyclohexanol acetate can be mentioned. These can be used alone or in combination of two or more.

[0073] The content of the solvent in the photosensitive conductive paste may be 3% by weight or more, and may be 5% by weight or more. The content of the solvent in the photosensitive conductive paste may be 20% by weight or less, and may be 15% by weight or less.

[0074] <Metal resinate> The photosensitive conductive paste may contain a metal resinate. This resinate is a metal resinate containing a metal having a melting point higher than the melting point of the conductive powder. Examples of the metal contained in the metal resinate include Rh, Ni, Cu, Mn, Zr, etc. Examples of such metal resinates include metal octylates, naphthenates, 2-ethylhexane salts, sulfonates, metal mercaptides, alkoxy metal compounds.

[0075] <Co-material> The photosensitive conductive paste may contain a co-material (non-conductive metal oxide), but from the viewpoint of improving the resolution during photolithography patterning and reducing the electrical resistance, the lower the content, the more preferable. The content of the co-material may be 3.0% by weight or less, may be 1.0% by weight or less, and may be 0% by weight with respect to the photosensitive conductive paste.

[0076] (Manufacturing method of multilayer electronic component) Next, the manufacturing method of the multilayer electronic component 10 will be described. The manufacturing method of the multilayer electronic component 10 includes a step of laminating the photosensitive conductive paste on the insulating layer 40, A step of sintering the photosensitive conductive paste and the insulating layer 40 at a firing temperature of 800 °C or higher, forming a coil 5 (internal electrode) from the photosensitive conductive paste, forming a body 4 from the insulating layer 40, providing the coil 5 in the body 4.

[0077] According to the above manufacturing method, the shrinkage behavior of the photosensitive conductive paste during firing can be made to correspond to the shrinkage behavior of the body material. Therefore, suppression of delamination can be expected.

[0078] Hereinafter, an example of a method for manufacturing the laminated electronic component 10 using the photosensitive conductive paste of the present disclosure will be specifically described.

[0079] As shown in FIG. 2, a glass paste as an insulating paste is screen-printed and dried on a support film such as a PET film, and this is repeated several times to obtain an insulating layer (glass layer) 40 having a predetermined thickness (for example, about 100 μm). In FIG. 2, the support film is omitted.

[0080] An insulating paste such as a glass paste contains an insulating inorganic component and an organic component. The glass paste contains, as the insulating inorganic component, for example, glass powder and ceramic aggregate (inorganic filler), and contains, as the organic component, for example, an acrylic polymer. As the organic component, a solvent, a dispersant, an antifoaming agent, etc. may be further contained.

[0081] The type of glass powder contained in the insulating paste is not particularly limited, but for example, a SiO2 - B2O3 - K2O - based glass containing SiO2, B2O3, and K2O in a predetermined ratio can be used. Two or more types of glass powder may be mixed and used. The average particle size of the glass powder is not particularly limited, but may be 0.1 μm or more and 5.0 μm or less.

[0082] The type of ceramic aggregate contained in the insulating paste is not particularly limited. For example, alumina can be used. Two or more types of ceramic aggregates may be mixed and used. The average particle size of the ceramic aggregate is not particularly limited, but it may be 0.1 μm or more and 5.0 μm or less.

[0083] Note that the insulating layer 40 may be produced by laminating a green sheet pre-formed into a sheet shape.

[0084] On the insulating layer 40, the photosensitive conductive paste of the present disclosure is screen-printed so as to have a film thickness of about 5 μm or more and 20 μm or less, dried, and then selectively exposed and developed to form the first-layer coil wiring 2.

[0085] From above the first-layer coil wiring 2, glass paste is screen-printed over the entire surface so as to have a film thickness of about 10 to 20 μm and dried. Subsequently, via holes 3 are formed at predetermined positions of the insulating layer 40 formed on the first-layer coil wiring 2. The via holes 3 are formed, for example, by laser processing, pattern printing, or, when the insulating paste has photolithography characteristics, by a patterning method.

[0086] Again, the photosensitive conductive paste of the present disclosure is screen-printed over the entire surface so as to have a film thickness of about 5 μm or more and 10 μm or less, dried, and then selectively exposed and developed to form the second-layer coil wiring 2.

[0087] The lamination of the insulating layer 40 and the coil wiring 2 is repeated until the desired number of layers is obtained.

[0088] Furthermore, the glass paste is screen-printed and dried over the entire surface the required number of times to form the insulating layer 40 on the topmost layer coil wiring 2. Thereby, a laminated structure is obtained in which the coil wirings 2 are interconnected between layers via the via holes 3.

[0089] After dividing the obtained laminated structure into chip shapes using a dicing saw, a support film such as a PET film is separated. Thereafter, it is fired at a temperature of 800°C or higher. By this firing, the photosensitive conductive paste is sintered to form the coil 5. Also, the insulating layer 40 is sintered to form the element body 4.

[0090] A first external electrode 6a and a second external electrode 6b are formed on the fired laminate. Further, a plating layer having a single-layer or laminated structure may be deposited on the outer surfaces of the first external electrode 6a and the second external electrode 6b by an electrolytic plating method, an electroless plating method, or the like.

[0091] As described above, the multilayer electronic component 10 shown in FIG. 1 is obtained.

[0092] [Second Embodiment] The second embodiment is different from the first embodiment in that the photosensitive conductive paste does not contain an organic flame retardant and that a cellulose derivative is included as the alkali-soluble polymer. This different configuration will be described below. Since the other configurations of the second embodiment are the same as those of the first embodiment, the description thereof is omitted. In the second embodiment, since the configuration of the electronic component and the method for manufacturing the electronic component are the same as those of the first embodiment, the description thereof is omitted.

[0093] In the present embodiment, a cellulose derivative is included as the alkali-soluble polymer. The cellulose derivative is less likely to be thermally decomposed compared with other alkali-soluble polymers (typically, carboxyl group-containing acrylic polymers). Thereby, the decomposition rate of the organic component is reduced, and at the beginning of firing, the shrinkage of the photosensitive conductive paste proceeds gently. As described above, the element body material also has a small shrinkage until the glass component softens. That is, the shrinkages of the photosensitive conductive paste and the element body material at the beginning of firing are both small, and the shrinkage behaviors of both correspond.

[0094] On the other hand, cellulose derivatives, like other organic components, also decompose upon heating. Therefore, when the decomposition temperature of the organic components is reached, the organic components containing the cellulose derivative rapidly decompose. That is, in the latter half of the firing stage, the decomposition of the organic components proceeds rapidly, causing the shrinkage of the photosensitive conductive paste. Thus, even in the latter half of the firing stage, the shrinkage behavior of the green body material and the shrinkage behavior of the photosensitive conductive paste correspond. Thereby, suppression of delamination can be expected.

[0095] The thermodegradability of the cured product of the organic component (hereinafter referred to as "second cured product") used in the photosensitive conductive paste according to the present disclosure in an oxygen atmosphere can satisfy the above conditions A and B.

[0096] The thermodegradability of the second cured product in an oxygen atmosphere may further satisfy the above condition C.

[0097] The second cured product is obtained by mixing each organic component at the ratio in which it is blended in the photosensitive conductive paste and curing. The second cured product may be obtained by curing a second mixture obtained by mixing a photosensitive monomer, an alkali-soluble polymer containing a cellulose derivative, and a photopolymerization initiator at the ratio in which they are blended in the photosensitive conductive paste, in the same manner as above.

[0098] The content of the photosensitive monomer in the second cured product is, for example, 30% by weight or more and 60% by weight or less. The content of the alkali-soluble polymer containing a cellulose derivative in the second cured product is, for example, 30% by weight or more and 60% by weight or less. The content of the photopolymerization initiator in the second cured product is, for example, 3% by weight or more and 10% by weight or less.

[0099] The cellulose derivative may have a water-soluble substituent. Examples of the water-soluble substituent include at least one selected from the group consisting of a hydroxyalkyl group, a carboxyalkyl group, a phthalic acid group, a sulfuric acid group, and a phosphoric acid group. Among them, it may be at least one of a hydroxyalkyl group and a carboxyalkyl group in terms of high alkali solubility.

[0100] Examples of cellulose derivatives having a water-soluble substituent include hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, hydroxyethyl carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxy methyl phthalic acid cellulose, hydroxypropyl methyl cellulose phthalate, hydroxypropyl methyl cellulose acetate phthalate, carboxymethyl cellulose, carboxymethyl ethyl cellulose, and hydroxypropyl methyl cellulose. These may be used alone or in combination of two or more.

[0101] The weight ratio of the cellulose derivative in the alkali-soluble polymer may be, for example, 5% by weight or more and 100% by weight or less. Thereby, the effect of reducing the decomposition rate of the organic component is easily exhibited. The weight ratio of the cellulose derivative in the alkali-soluble polymer may be 20% by weight or more, and may be 40% by weight or more. The weight ratio of the cellulose derivative in the alkali-soluble polymer may be 100% by weight, may be 90% by weight or less, and may be 80% by weight or less.

[0102] [Third Embodiment] The third embodiment is different from the first embodiment in that it contains a cellulose derivative as an alkali-soluble polymer. This different configuration will be described below. Since the other configurations of the third embodiment are the same as those of the first embodiment, the description thereof will be omitted. In the third embodiment, since the configuration of the electronic component and the manufacturing method of the electronic component are the same as those of the first embodiment, the description thereof will be omitted.

[0103] In this embodiment, the photosensitive conductive paste contains a cellulose derivative as an alkali-soluble polymer together with an organic flame retardant. Thereby, the decomposition rate of the organic component is more easily reduced. The content of the organic flame retardant is the same as in the first embodiment. The weight ratio of the cellulose derivative in the alkali-soluble polymer is the same as in the second embodiment. Examples of the cellulose derivative are the same as those in the second embodiment.

[0104] Also in this case, the thermodegradability of the cured product of the organic components (photosensitive monomer, alkali-soluble polymer including cellulose derivative, photoinitiator, and organic flame retardant) used in the photosensitive conductive paste according to the present disclosure (hereinafter referred to as "third cured product") can satisfy the above conditions A and B.

[0105] The thermodegradability of the third cured product in an oxygen atmosphere may further satisfy the above condition C.

[0106] The third cured product is obtained by mixing each organic component at a ratio compounded in the photosensitive conductive paste and curing. The third cured product may be obtained by curing a third mixture obtained by mixing a photosensitive monomer, an alkali-soluble polymer including a cellulose derivative, a photoinitiator, and an organic flame retardant at a ratio compounded in the photosensitive conductive paste, in the same manner as above.

[0107] The content of the photosensitive monomer in the third mixture is, for example, 30% by weight or more and 60% by weight or less. The content of the alkali-soluble polymer including the cellulose derivative in the third mixture is, for example, 30% by weight or more and 60% by weight or less. The content of the photoinitiator in the third mixture is, for example, 3% by weight or more and 10% by weight or less. The content of the organic flame retardant in the third mixture is, for example, 1% by weight or more and 30% by weight or less.

[0108] Note that the present disclosure is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present disclosure.

Examples

[0109] Hereinafter, the present disclosure will be described more specifically with reference to examples. However, the present disclosure is not limited by the following examples, and it is of course possible to make appropriate changes and implement them within the scope applicable to the gist of the foregoing and following descriptions, and all of them are included in the technical scope of the present disclosure.

[0110] [Examples 1 to 7, Comparative Examples 1 to 2] (1) Preparation of photosensitive resin 25% by weight of a photosensitive monomer (dipentaerythritol hexa (meth) acrylate), 4% by weight of a photoinitiator (α - aminoalkylphenone - based), 1% by weight of an antifoaming agent, an alkali - soluble polymer, a flame retardant, etc. were blended at the ratios shown in Table 1 and mixed thoroughly to obtain photosensitive resins A - H containing organic components and a solvent. In Table 1, the remainder of the blend is a solvent (cyclohexanol acetate). Using each of the photosensitive resins A - H, photosensitive conductive pastes of Examples 1 - 7 and Comparative Examples 1 - 2 were prepared respectively.

[0111]

Table 1

[0112] (2) Preparation of photosensitive conductive paste 80% by weight of conductive powder, 18% by weight of each photosensitive resin (A - H), and 2% by weight of a dispersant were blended and thoroughly mixed with a three - roll mill to obtain a photosensitive conductive paste for forming an internal electrode. For the photosensitive conductive pastes of Examples 1 - 7 and Comparative Example 1, Ag powder with an average particle size D50 of 2.0 μm was used, and for the photosensitive conductive paste of Comparative Example 2, Ag powder with an average particle size D50 of 0.8 μm was used.

[0113] [Evaluation] (1) Weight loss rate Each component other than the solvent and the antifoaming agent was mixed at the same ratios as the photosensitive resins A - H shown in Table 1 to obtain an organic component. This organic component was irradiated with ultraviolet light to obtain a cured product. Using a thermogravimetric analyzer, in an oxygen atmosphere, ΔTG at 300 °C and 400 °C of each cured product, and the temperature T Δ100 at which 100% weight loss occurred were measured.

[0114] (2) Preparation and measurement of specific resistance evaluation samples The photosensitive conductive paste was screen-printed and dried on an alumina substrate with a film thickness of 10 μm or more and 20 μm or less, then exposed through a photomask having a wiring pattern, and developed with an alkaline aqueous solution to form a wiring pattern. The formed wiring pattern was fired at 900 °C for 60 minutes to fabricate electrode wirings for resistance measurement. The resistance value, line width, line length, and film thickness of the obtained wiring samples were measured. Based on the volume of the Ag in the calculated volume of the wiring, the specific resistance value was calculated. Those with a specific resistance value of 2.2 μΩ·cm or less were rated as A (qualified, good), and those exceeding 2.2 μΩ·cm were rated as B (unqualified).

[0115] (3) Fabrication and measurement of samples for evaluating the firing shrinkage rate The photosensitive conductive paste prepared by the above method was printed on a smooth substrate and dried, then exposed through a photomask having a wiring pattern, and developed with an alkaline aqueous solution to form a wiring pattern. The volume of the wiring pattern of the obtained paste was calculated using a laser displacement meter. Next, these dot patterns were heat-treated at 700 °C. The volume of the wiring pattern of the heat-treated samples was calculated again using a laser displacement meter. Based on the volume values before and after the heat treatment, the percentage reduction in volume due to the heat treatment was calculated, and this value was defined as the firing shrinkage rate.

[0116] In the heat treatment at 700 °C, the photosensitive resins A to H were completely decomposed. Typically, the shrinkage of the bare body 4 containing no organic components was small. Therefore, the fact that the shrinkage rate of the photosensitive conductive paste (i.e., the internal electrode) after heat treatment at 700 °C is small also indicates that delamination is suppressed.

[0117] Those with a shrinkage rate at 700 °C of less than 30% were rated as A (qualified, better), those with a shrinkage rate of 30% or more and less than 40% were rated as B (qualified, good), and those with a shrinkage rate of 40% or more were rated as C (unqualified).

[0118] (4) Patterning property (resolution) After screen-printing the photosensitive conductive paste onto an alumina substrate, drying was carried out at 60 °C for 30 minutes to form a photosensitive conductive paste film with a film thickness of 10 μm. Next, light from an ultra-high pressure mercury lamp (manufactured byUSHIO INC.) was irradiated through a photomask with a linear pattern of L / S = 25 / 25 μm onto the substrate at 1000 mJ / cm 2 (405 nm) to perform a mask exposure process on the photosensitive conductive paste film. Thereafter, development treatment was carried out with an aqueous triethanolamine solution. Those that could be formed without residue and line skipping were designated as A (qualified), and those with line skipping were designated as B (unqualified).

[0119] The evaluation results are shown in Table 2. Table 2 also shows the presence or absence of a flame retardant and a cellulose derivative.

[0120]

Table 2

[0121] The photosensitive conductive paste of the example satisfies the above conditions A and B, has a small firing shrinkage rate at a firing temperature of 700 °C, and can be expected to suppress delamination. Furthermore, the photosensitive conductive paste used in the example satisfies the above condition C, and the shrinkage of the photosensitive conductive paste proceeds gently until degreasing is completed, and suppression of delamination can be further expected.

[0122] In addition, since the photosensitive conductive paste of the example does not contain a co-material, the specific resistance after firing is small and the patterning property is good. Therefore, it can be seen that the electrical resistance is low and the resolution during photolithographic patterning is improved.

[0123] In contrast, the photosensitive conductive paste of Comparative Example 1 did not contain a flame retardant and a cellulose derivative and contained a co-material. Therefore, although the firing shrinkage rates at firing temperatures of 300 °C and 400 °C were small, the specific resistance increased and the patterning property was poor. The photosensitive conductive paste of Comparative Example 2 did not contain a flame retardant and a cellulose derivative and contained Ag powder with a small particle size. Therefore, the firing shrinkage rates at firing temperatures of 300 °C and 400 °C were small and the specific resistance was also small, but the patterning property was poor.

[0124] <1> A photosensitive conductive paste comprising a conductive powder, an organic component, and a solvent, wherein the organic component includes an alkali-soluble polymer, a photosensitive monomer, a photopolymerization initiator, and an organic flame retardant. <2> A photosensitive conductive paste comprising a conductive powder, an organic component, and a solvent, wherein the organic component includes an alkali-soluble polymer, a photosensitive monomer, and a photopolymerization initiator, The photosensitive conductive paste, wherein the alkali-soluble polymer includes a cellulose derivative. <3> The photosensitive conductive paste according to <1>, wherein the alkali-soluble polymer includes a cellulose derivative. <4> The photosensitive conductive paste according to <1> or <3>, wherein the organic flame retardant includes at least one selected from the group consisting of a phosphate ester compound, a thioether compound, a nitrogen-containing aromatic compound, a brominated hydrocarbon compound, and a chlorinated hydrocarbon compound. <5> The photosensitive conductive paste according to <1>, <3>, or <4>, wherein the organic flame retardant includes at least one of a thioether compound and a chlorinated hydrocarbon compound. <6> The photosensitive conductive paste according to any one of <2> to <5>, wherein the cellulose derivative has a water-soluble substituent. <7> The photosensitive conductive paste according to any one of <1> to <6>, wherein the thermal decomposability of the cured product of the organic component in an oxygen atmosphere satisfies the following Condition A and Condition B. (Condition A) In thermogravimetric measurement, the weight loss rate at 300 °C is less than 50%. (Condition B) In thermogravimetric measurement, the weight loss rate at 700 °C is 100%. <8> The photosensitive conductive paste of <7> in which the weight loss rate at 300 °C in the above Condition A is less than 30%. <9> The photosensitive conductive paste of <7> or <8> in which the weight loss rate at 600 °C in the above Condition B is 100%. <10> The photosensitive conductive paste of any one of <7> to <9> in which the thermal decomposability of the cured product in an oxygen atmosphere satisfies the following Condition C. (Condition C) In thermogravimetric measurement, the change in the weight loss rate in the range of 300 °C or higher and 400 °C or lower is 70% or less. <11> The conductive powder is silver powder, and the photosensitive conductive paste of any one of <1> to <10>. <12> The photosensitive conductive paste of <11> in which the average particle diameter D50 of the silver powder is 0.5 μm or more and 5.0 m or less. <13> A step of laminating the photosensitive conductive paste according to any one of <1> to <12> on an insulating layer; A step of sintering the photosensitive conductive paste and the insulating layer at a firing temperature of 800 °C or higher, and Forming an internal electrode from the photosensitive conductive paste, Forming a body from the insulating layer, A method for manufacturing a multilayer electronic component, in which the internal electrode is provided in the body. <14> A body containing borosilicate glass and an inorganic filler, and An internal electrode provided in the body and being a sintered body of the photosensitive conductive paste according to any one of <1> to <12>, a multilayer electronic component.

Description of Symbols

[0125] 2 Coil Wiring 3 via holes 4 Body 5 Coil 5a First End 5b Second End 6a First External Electrode 6b Second External Electrode 10 Multilayer Electronic Component 40 Insulating Layer 41, 42 First End Face, Second End Face 43, 44 First Side Face, Second Side Face 45 Bottom Surface 46 Top Surface

Claims

1. A photosensitive conductive paste comprising conductive powder, an organic component, and a solvent, wherein the organic component includes an alkali-soluble polymer, a photosensitive monomer, a photopolymerization initiator, and an organic flame retardant.

2. A photosensitive conductive paste comprising conductive powder, an organic component, and a solvent, wherein the organic component includes an alkali-soluble polymer, a photosensitive monomer, and a photopolymerization initiator, and wherein the alkali-soluble polymer includes a cellulose derivative.

3. The photosensitive conductive paste according to claim 1, wherein the alkali-soluble polymer includes a cellulose derivative.

4. The photosensitive conductive paste according to claim 1 or 3, wherein the organic flame retardant includes at least one selected from the group consisting of a phosphate ester compound, a thioether compound, a nitrogen-containing aromatic compound, a brominated hydrocarbon compound, and a chlorinated hydrocarbon compound.

5. The photosensitive conductive paste according to claim 1 or 3, wherein the organic flame retardant includes at least one of a thioether compound and a chlorinated hydrocarbon compound.

6. The photosensitive conductive paste according to claim 2 or 3, wherein the cellulose derivative has a water-soluble substituent.

7. The photosensitive conductive paste according to claim 1 or 2, wherein the thermal decomposability of the cured product of the organic component satisfies the following Conditions A and B. (Condition A) In thermogravimetric measurement, the weight loss rate at 300 °C is less than 50%. (Condition B) In thermogravimetric measurement, the weight loss rate at 700 °C is 100%.

8. The photosensitive conductive paste according to claim 7, wherein the weight loss rate at 300 °C in Condition A is less than 30%.

9. The photosensitive conductive paste according to claim 7, wherein the weight loss rate at 600 °C in Condition B is 100%.

10. The photosensitive conductive paste according to claim 7, wherein the thermal decomposability of the cured product in an oxygen atmosphere satisfies the following Condition C. (Condition C) In thermogravimetric measurement, the change in the weight loss rate in the range of 300 °C or more and 400 °C or less is 70% or less.

11. The photosensitive conductive paste according to claim 1 or 2, wherein the conductive powder is silver powder.

12. The photosensitive conductive paste according to claim 11, wherein the average particle diameter D50 of the silver powder is 0.5 μm or more and 5.0 m or less.

13. A step of laminating the photosensitive conductive paste according to claim 1 or 2 on an insulating layer, A step of sintering the photosensitive conductive paste and the insulating layer at a firing temperature of 800°C or higher, and forming an internal electrode from the photosensitive conductive paste, forming a body from the insulating layer, A method for manufacturing a multilayer electronic component, wherein the internal electrode is provided in the body.

14. A body including borosilicate glass and an inorganic filler, and An internal electrode provided in the body and being a sintered body of the photosensitive conductive paste according to claim 1 or 2. A multilayer electronic component comprising the same.

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