JP2022154879A - Electronic part production kit and use thereof - Google Patents

Abstract

To provide a technique capable of stably producing an electronic part having a precise conductive layer.SOLUTION: The production kit comprises a paste for substrate formation and a photosensitive conductive paste. In the electronic part production kit, an HSP distance between a binder resin of the paste for substrate formation, and an organic solvent of the photosensitive conductive paste, is 1.0 or greater and 2.5 or smaller. In addition, an HSP distance between the binder resin of the paste for substrate formation and a surface treatment agent of conductive inorganic powder of the photosensitive conductive paste is 1.0 or greater. Therefore, sheet attack of the photosensitive conductive paste to a green sheet can be properly controlled, and adhesion of the conductive inorganic powder to the green sheet surface via the surface treatment agent, can be suppressed. As the result, generation of a residue can be preferably suppressed while securing a long development margin. Therefore, an electronic part having a precise conductive layer can be stably produced.SELECTED DRAWING: None

Description

The present invention relates to an electronic component manufacturing kit. Specifically, the present invention relates to an electronic component manufacturing kit having a substrate forming paste for forming an inorganic substrate of an electronic component and a photosensitive conductive paste for forming a conductive layer on the surface of the inorganic substrate.

Electronic components such as high-frequency inductors generally have an insulating inorganic base material and a linear conductive layer formed on the surface of the inorganic base material in a predetermined pattern. A photolithographic method has been proposed as one of the methods for manufacturing these electronic components. In such a photolithography method, for example, a paste for forming a base material containing an insulating inorganic powder and a binder resin, and a photosensitive conductive paste containing a conductive inorganic powder, a photocurable resin, and an organic solvent for electronic component manufacturing A kit (hereinafter also simply referred to as a "production kit") is used.

In manufacturing an electronic component using the manufacturing kit, first, a green sheet, which is a precursor of an inorganic base material, is formed using a base material forming paste. Then, a layer of photosensitive conductive paste is applied to the surface of the green sheet and dried to form a film. Next, the film is covered with a photomask having slits (openings) of a predetermined pattern, and a part of the film that is exposed from the slits is irradiated with light to form a photocured film. Next, a developing process is performed to remove the unexposed portion (uncured film-like body) shielded by the photomask with a developing solution. As a result, a photocured film having a predetermined pattern remains on the surface of the green sheet. By firing the photocured film and the green sheet, an electronic component having a conductive layer with a predetermined pattern is manufactured.

Patent Literature 1 discloses an example of technology for manufacturing electronic components using a photolithography method. In the technique described in Patent Document 1, a conductive paste is used in which the viscosity of the reactive compound (photocurable resin) at 60° C. is adjusted within the range of 5.0 Pa·s to 100.0 Pa·s. . As a result, absorption of the reactive compound in the photosensitive conductive paste into the green sheet can be suppressed, and a high-definition pattern can be formed. Further, in the technique described in Patent Document 1, the solubility parameter (SP value) of the solvent (organic solvent) of the photosensitive conductive paste is within the range of 19.5 to 21.3 (J/cm ³ ) ^1/2 . adjusted. As a result, it is possible to obtain the effects of suppressing the remaining unexposed portions (residue generation) after development and facilitating the formation of a highly finely patterned conductive layer (development of the photocured film).

Patent No. 6662491

However, there is still room for improvement in manufacturing electronic components using photolithography. Specifically, even when the solubility of the organic solvent is adjusted as described in Patent Document 1, there are problems such as the generation of residues after development processing and the reduction in ease of development due to shortened development margins. something happened. In addition, the "development margin" is the time from the time when the unexposed portion is completely removed (Break Point (B.P.)) to the time when peeling or disconnection occurs in the exposed portion (photocured film) in the development process. It's time for That is, if the development margin is shortened, peeling or the like of the photocured film occurs immediately after the unexposed portion is removed, making it difficult to precisely develop the photocured film (conductive layer).

The present invention has been made to solve the above-mentioned problems, and its object is to suppress the generation of residues after development processing, secure a sufficiently long development margin, and provide an electronic device having a precise conductive layer. It is to provide a technology that can stably manufacture parts.

As described above, even when the solubility of the organic solvent of the photosensitive conductive paste is adjusted according to the technique described in Patent Document 1, the generation of residue and shortening of the development margin may occur. The present inventors have obtained the following findings as a result of examining the causes of such problems.

First, in the manufacture of an electronic component, a green sheet is molded using a substrate-forming paste, and a photosensitive conductive paste is applied to the surface of the green sheet. At this time, part of the organic solvent of the photosensitive conductive paste may dissolve into the green sheet, causing sheet attack that dissolves the binder resin of the green sheet. When this sheet attack occurs appropriately, the fixability of the photocured film on the surface of the green sheet is improved, and peeling of the photocured film during development is suppressed, so that the development margin is lengthened. On the other hand, if the sheet attack becomes excessive, not only the photocured film but also the fixability of the unexposed portion is increased, so that the unexposed portion remains after development processing (residue generation). The present inventor presumed that the reason why the frequency of residue generation and the length of the development margin changes when the solubility of the organic solvent of the photosensitive conductive paste is adjusted is that the degree of sheet attack described above fluctuates. However, the sheet attack is due to the interaction between the organic solvent of the photosensitive conductive paste and the binder resin of the paste for base material formation (green sheet). Therefore, even if only the solubility of the organic solvent of the photosensitive conductive paste is adjusted as in Patent Document 1, it is difficult to accurately control the degree of sheet attack. Based on such findings, the inventors of the present invention have found that the degree of sheet attack can be accurately controlled by mutually adjusting both the solubility of the organic solvent in the photosensitive conductive paste and the solubility of the binder resin in the base-forming paste. I came up with

As a result of further studies, the inventors of the present invention have found that post-development residue can be caused by factors other than sheet attack. Specifically, a surface treatment agent is added to the particle surfaces of a typical conductive inorganic powder to suppress aggregation of the particles. Depending on the combination of the conductive inorganic powder surface treatment agent and the binder resin of the green sheet, the conductive inorganic powder may adhere to the surface of the green sheet via the surface treatment agent. In this case, even if excessive sheet attack can be prevented and the organic components in the unexposed areas can be appropriately removed in the development process, the conductive inorganic powder directly adhering to the surface of the green sheet may become a residue. . Based on such findings, the inventors of the present invention have found that if the degree of sheet attack can be appropriately controlled and the adhesion between the green sheet and the conductive inorganic powder via the surface treatment agent can be suppressed, the generation of residue can be suppressed. I thought it could be controlled properly.

The electronic component manufacturing kit disclosed herein is based on the above findings. Such a production kit includes a substrate-forming paste (A) for forming an insulating inorganic substrate and a photosensitive conductive paste (B) for forming a conductive layer on the surface of the inorganic substrate. . The base material forming paste (A) contains an insulating inorganic powder (A1) and a binder resin (A2). On the other hand, the photosensitive conductive paste (B) includes a conductive inorganic powder (B1) having a surface treatment agent attached to the particle surface, a photocurable resin (B2), a photopolymerization initiator (B3), and an organic solvent ( B4). In the electronic component manufacturing kit disclosed herein, the HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is It is 1.0 or more and 2.5 or less. Furthermore, the HSP distance between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) is 1.0 or more. .

Here, "HSP distance" as used herein is the absolute value of the difference in Hansen Solubility Parameters (HSP values) between two components. Specifically, the HSP value consists of energy due to intermolecular dispersion force (dispersion term dD), energy due to intermolecular dipole interaction (polarity term dP), and energy due to intermolecular hydrogen bonding (hydrogen bond term dH) is a parameter that defines the solubility by three factors. Each of these three elements can be plotted in a three-dimensional space (Hansen space). Then, the point (0, 0, 0) in the Hansen space is the starting point and the plotted coordinates (dD, dP, dH) are the ending point, and the distance between the coordinates from the starting point to the ending point is the "HSP value". . The "HSP distance" is the distance between the coordinates of the two components in the Hansen space, and can be calculated based on the following formula. In the following formula, “dD ₁ ” is the dispersion term of one substance (the first substance), “dP ₁ ” is the polar term of the first substance, and “dH ₁ ” is the hydrogen bonding term of the first substance. is. Then, “dD ₂ ” is the dispersion term of the other substance (second substance), “dP ₂ ” is the polar term of the second substance, and “dH ₂ ” is the hydrogen bonding term of the second substance. . The HSP value and HSP distance in this specification are both values at 25° C., and the unit is (J/cm ³ ) ^1/2 .
HSP distance = [4 x (dD ₁ - dD ₂ ) ² + (dP ₁ - dP ₂ ) ² + (dH ₁ - dH ₂ ) ² ] ^1/2

And when the HSP distance between two components is small, it can be said that the two components are likely to dissolve in each other. Here, in the manufacturing kit having the above configuration, the upper limit of the HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is adjusted to 2.5 or less. As a result, the binder resin (A2) is appropriately dissolved in the organic solvent (B4) to cause sheet attack, so that a sufficiently long development margin can be secured. On the other hand, it can be said that two components with a large HSP distance are difficult to dissolve in each other. In the manufacturing kit having the above configuration, the lower limit of the HSP distance between the binder resin (A2) and the organic solvent (B4) is adjusted to 1.0 or more. As a result, since excessive sheet attack can be prevented, it is possible to suppress the generation of residue due to increased fixability of the unexposed portion on the surface of the green sheet. Furthermore, since the HSP distance is calculated based on the dispersion term dD, the polar term dP and the hydrogen bonding term dH, not only the solubility between the two components but also the adhesion of the two components can be evaluated. . Here, in the manufacturing kit having the above configuration, the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) HSP distance is adjusted to 1.0 or more. As a result, adhesion between the green sheet and the conductive inorganic powder (B1) through the surface treatment agent is less likely to occur, so that the generation of residue can be more suitably suppressed. As described above, according to the electronic component manufacturing kit disclosed herein, it is possible to suitably suppress the generation of residues while ensuring a sufficiently long development margin, so that electronic components having precise conductive layers can be manufactured stably. can be realized.

In a preferred embodiment of the electronic component manufacturing kit disclosed herein, the binder resin (A2) of the base material forming paste (A) and the surface of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) The HSP distance to the treating agent is 3.5 or less. This makes it possible to easily secure a longer development margin.

In addition, in the electronic component manufacturing kit disclosed herein, the HSP value itself of each component is not particularly limited as long as the HSP distance between each component satisfies the above-described range. For example, the HSP value of the binder resin (A2) can be 17.0-22.0. Also, the HSP value of the organic solvent (B4) may be 17.0 to 21.0. The HSP value of the surface treatment agent of the conductive inorganic powder (B1) can be 17.5-21.0.

In a preferred aspect of the electronic component manufacturing kit disclosed herein, the conductive inorganic powder (B1) contains silver-based particles. As a result, it is possible to manufacture an electronic component with an excellent balance between cost and electrical resistance.

Moreover, as another aspect of the technology disclosed herein, a photosensitive conductive paste used in the manufacturing kit having the above configuration is provided. Such a photosensitive conductive paste (B) includes a conductive inorganic powder (B1) having a surface treatment agent attached to the surface, a photocurable resin (B2), a photopolymerization initiator (B3), and an organic solvent (B4). including. The HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is 1.0 or more and 2.5 or less, and The HSP distance between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) is 1.0 or more.

Also, as another aspect of the technology disclosed herein, a method for manufacturing an electronic component is provided. Such a method for manufacturing an electronic component is a method for manufacturing an electronic component using the manufacturing kit configured as described above. The method for manufacturing such an electronic component includes a green sheet preparation step of preparing a green sheet formed by forming a base material paste (A) into a sheet shape, and applying a photosensitive conductive paste (B) to the surface of the green sheet, A filmy body forming step of forming a filmy body by drying the photosensitive conductive paste (B), covering the filmy body with a photomask having slits of a predetermined pattern, and part of the filmy body exposed from the slits An exposure step of irradiating light to form a photocured film, a developing step of removing the uncured film-like body shielded by the photomask with a developer, a green sheet, and residual on the surface of the green sheet and a baking step of baking the photocured film.

FIG. 4 is a cross-sectional view for explaining a film-like body forming step in the method for manufacturing an electronic component according to one embodiment; It is a sectional view explaining an exposure process in a manufacturing method of electronic parts concerning one embodiment. It is a sectional view explaining a development process in a manufacturing method of electronic parts concerning one embodiment.

Preferred embodiments of the technology disclosed herein are described below. Matters other than those specifically mentioned in this specification, which are necessary for the implementation of the technology disclosed herein, are based on the technical content taught by this specification and those skilled in the art. can be understood based on general technical common sense. The technology disclosed herein can be implemented based on the content disclosed in this specification and common general technical knowledge in the field. In addition, the notation of "A to B" (A and B are arbitrary numbers) indicating the range in this specification means "preferably larger than A" and "preferably smaller than B" along with the meaning of A or more and B or less. shall include the meaning of

1. Electronic Component Manufacturing Kit First, the electronic component manufacturing kit disclosed herein will be described. In this specification, the term "electronic component manufacturing kit" refers to a combination of multiple types of paste compositions used for manufacturing electronic components. As used herein, "paste" is a term that encompasses inks and slurries. The manufacturing kit disclosed herein includes at least a base-forming paste (A) and a photosensitive conductive paste (B). The components of each paste will be specifically described below.

(1) Base material forming paste (A)
The base-forming paste (A) is a paste for forming an insulating inorganic base. This base material forming paste (A) contains at least an insulating inorganic powder (A1) and a binder resin (A2). A green sheet, which is a precursor of the inorganic base material, can be produced by forming the paste (A) for base material formation into a sheet. When the green sheet is fired, the binder resin (A2) is burned off and the insulating inorganic powder (A1) is sintered to form an inorganic substrate. The components of the base-forming paste (A) are described below.

(1-1) Insulating inorganic powder (A1)
The insulating inorganic powder (A1) is an inorganic material that becomes the main component of the inorganic base material after firing. The insulating inorganic powder (A1) can be used without any particular limitation as long as it has a predetermined insulating property and remains without being burned off in the firing process. Examples of such insulating inorganic powder (A1) include oxide-based ceramics such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), zirconia (ZrO ₂ ), and titania (TiO ₂ ). Other examples of the insulating inorganic powder (A1) include nitride-based ceramics such as aluminum nitride (AlN) and silicon nitride _{( Si3N4} ). Moreover, when forming a transparent substrate as an inorganic base material, a glass powder can also be used as an insulating inorganic powder (A1). Preferred examples of such glass powder include SiO ₂ -based glass containing a silicon component (SiO ₂ ) as a main component. Specific examples of such SiO ₂ -based glasses include B ₂ O ₃ -SiO ₂ -based glasses, SiO ₂ -RO -based glasses (R is a Group 2 element (Mg, Ca, Sr, Ba, Ra, etc.)), SiO ₂ - RO—Al ₂ O ₃ based glass, SiO ₂ —RO—Y ₂ O ₃ based glass, SiO ₂ —RO—B ₂ O ₃ based glass, SiO ₂ —Al ₂ O ₃ based glass, SiO ₂ —ZnO based glass, Examples include SiO ₂ —ZrO ₂ based glass. Other examples of glass powder include RO-based glass, lead-based glass, lead-lithium-based glass, and the like.

The particle size of the insulating inorganic powder (A1) in the base material forming paste (A) is not particularly limited, but micron size is preferable. For example, from the viewpoint of ease of sheet molding and sintering, the lower limit of the _D50 particle size of the insulating inorganic powder (A1) is preferably 1 µm or more, more preferably 2 µm or more, and particularly preferably 3 µm or more. On the other hand, from the viewpoint of reducing the surface roughness of the substrate after firing, the upper limit of the _D50 particle size of the insulating inorganic powder (A1) is preferably 10 μm or less, more preferably 8 μm or less, and particularly preferably 5 μm or less. . The " _D50 particle size" in this specification is a particle size corresponding to an integrated value of 50% from the smaller particle size side in the volume-based particle size distribution based on the laser diffraction/scattering method.

The content of the insulating inorganic powder (A1) in the base-forming paste (A) is preferably 15% by mass or more, more preferably 20% by mass or more, further preferably 25% by mass or more, and 30% by mass or more. is particularly preferred. As a result, the resin component on the substrate surface can be reduced, and excessive sheet attack can be suppressed. On the other hand, the upper limit of the content of the insulating inorganic powder (A1) is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 35% by mass or less. This makes it possible to secure a resin component that can easily form the electrodes. In addition, unless otherwise specified, the "content" in this specification refers to the mass ratio (% by mass) when the total weight of the paste is 100% by mass.

(1-2) Binder resin (A2)
The binder resin (A2) is added to retain the shape of the green sheet before firing. As the binder resin (A2), a resin material is used which has a predetermined viscosity and which is burnt out during the baking process. Examples of such resin materials include butyral resins, vinyl resins, cellulose resins, alkyd resins, acrylic resins, epoxy resins, fluorine resins, silicone resins, polyester resins, ketone resins, polyamide resins, coumarone resins, and polyimide resins. Also, the binder resin (A2) may be a mixture of two or more of these resin materials. Among the resin materials mentioned above, butyral resin is preferable. Butyral resins are polymers containing butyral, hydroxyl, and acetate groups as the structure of the monomer units. An example of such a butyral resin is a polyvinyl butyral resin (PVB) obtained by reacting polyvinyl alcohol and butyraldehyde. However, the specific component of the binder resin (A2) is not particularly limited as long as it satisfies the conditions regarding the HSP distance described later, and conventionally known resin materials that can function as a binder can be used without particular limitation. For example, as commercially available binder resins, those sold by Shin-Nakamura Chemical Co., Ltd., Mitsubishi Chemical Co., Ltd., Shin-Etsu Chemical Co., Ltd., etc. can be used.

In addition, the lower limit of the content of the binder resin (A2) in the paste (A) for base material formation is suitably 5% by mass or more. As a result, the organic solvent (B4) of the photosensitive conductive paste (B), which will be described later, can appropriately cause sheet attack to dissolve the binder resin (A2) of the green sheet. In consideration of the shape stability of the green sheet, the lower limit of the content of the binder resin (A2) is preferably 6% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more. On the other hand, considering the denseness of the inorganic substrate after firing, the upper limit of the content of the insulating inorganic powder (A1) is preferably 20% by mass or less, more preferably 17% by mass or less, and further 15% by mass or less. preferable.

(1-3) Dispersion medium (A3)
Moreover, the base material forming paste (A) may contain a dispersion medium (A3) for dispersing the components described above. The dispersion medium (A3) is a liquid component that imparts appropriate viscosity and fluidity to the paste and improves handleability and moldability. However, in the base-forming paste (A) disclosed herein, the dispersion medium (A3) is not an essential component. That is, at the time of mixing each component other than the dispersion medium (A3) (for example, the insulating inorganic powder (A1) and the binder resin (A2)), it is possible to obtain viscosity and fluidity to the extent that the green sheet can be molded. If possible, it is not necessary to add a dispersing medium (A3). Therefore, the content of the dispersion medium (A3) in the base-forming paste (A) can be adjusted in consideration of the moldability of the green sheet. For example, the content of the dispersion medium (A3) in the substrate-forming paste (A) is generally 0% to 70% by mass, typically 15% to 65% by mass, for example 30% to 60% by mass. can be

Further, the type of dispersion medium (A3) is not particularly limited, and conventionally known organic dispersion mediums can be used alone or in combination of two or more. Examples of such organic dispersion media include alcohol solvents such as terpineol; glycol solvents such as ethylene glycol, propylene glycol and diethylene glycol; ether solvents such as dipropylene glycol methyl ether and methyl cellosolve (ethylene glycol monomethyl ether); Diethylene glycol monobutyl ether acetate, butyl carbitol acetate (diethylene glycol monobutyl ether acetate), ester solvents such as isobornyl acetate; toluene, xylene, naphtha, hydrocarbon solvents such as petroleum hydrocarbons; mineral spirits; be done. The dispersion medium (A3) may be selected in consideration of its boiling point. For example, by using a dispersion medium (A3) having a boiling point of 150° C. or higher, spontaneous evaporation of the dispersion medium (A3) can be prevented and the preservation stability of the paste can be improved. On the other hand, when a dispersion medium (A3) having a boiling point of 250° C. or less is used, the dispersion medium (A3) can be easily removed in the drying treatment after molding the green sheet.

(1-4) Other Components The base-forming paste (A) may contain components other than the components described above as long as the effect of the technology disclosed herein is not significantly impaired. The other component is not particularly limited, and conventionally known additives can be used alone or in combination of two or more. Such other additives include antioxidants, plasticizers, surfactants, leveling agents, thickeners, dispersants, defoamers, anti-gelling agents, stabilizers, preservatives, and the like.

(2) Photosensitive conductive paste (B)
Next, the photosensitive conductive paste (B) will be explained. The photosensitive conductive paste (B) disclosed here is a paste for forming a conductive layer on the surface of an inorganic substrate. This photosensitive conductive paste (B) contains at least a conductive inorganic powder (B1), a photocurable resin (B2), a photopolymerization initiator (B3), and an organic solvent (B4). .

(2-1) Conductive inorganic powder (B1)
The conductive inorganic powder (B1) is an inorganic powder that becomes the main component of the conductive layer after firing. The conductive inorganic powder (B1) can be used without particular limitation as long as it has a predetermined electrical conductivity and remains without being burned off in the firing treatment. Examples of such conductive inorganic powder (B1) include gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), aluminum (Al), nickel (Ni), ruthenium (Ru ), rhodium (Rh), tungsten (W), iridium (Ir), osmium (Os), and compounds and alloys containing these. In addition, a suitable example of the conductive inorganic powder (B1) includes silver-based particles. The term “silver-based particles” encompasses all particulate materials containing silver (Ag) element. Examples of such silver-based particles include particles composed of silver alone, particles composed of a silver alloy, core-shell particles containing a silver component, and the like. Examples of silver alloys include silver-palladium (Ag-Pd) alloys, silver-platinum (Ag-Pt) alloys, silver-copper (Ag-Cu) alloys, and the like. Examples of the core-shell particles include silver-ceramic core-shell particles having a core particle containing elemental silver and a ceramic shell covering the core particle. Since these silver-based particles are relatively inexpensive and have high electrical conductivity, they can contribute to the production of electronic components having an excellent balance between electrical conductivity and cost.

Moreover, in the photosensitive conductive paste (B) disclosed herein, a conductive inorganic powder (B1) having a surface treating agent attached to the particle surface is used. As a result, aggregation of the particles can be suppressed and the dispersibility of the particles in the paste can be improved, which can contribute to uniform density of the conductive layer after firing. Examples of surface treatment agents include organic acids, surfactants, organometallic compounds, chelating agents, and polymer dispersants. Examples of the above organic acids include fatty acids such as propionic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, acrylic acid, oleic acid, linoleic acid, arachidonic acid and ricinoleic acid. Salts of these organic acids (organic acid salts) can also be used as surface treatment agents. Chelating agents include azoles such as benzotriazole or salts thereof, succinic acid, malonic acid, glutaric acid, and adipic acid. However, the specific component of the surface treatment agent is not particularly limited as long as it satisfies the conditions regarding the HSP distance described later, and a conventionally known organic component that can function as a surface treatment agent for the conductive inorganic powder (B1) Can be used without restrictions.

Although not particularly limited, the upper limit of the _D50 particle size of the conductive inorganic powder (B1) is preferably 5 µm or less, more preferably 4.5 µm or less, and particularly preferably 4 µm or less. As the particle size of the conductive inorganic powder (B1) becomes smaller, the denseness of the conductive layer after firing tends to improve. On the other hand, if the particle size of the conductive inorganic powder (B1) is too small, coarse particles are likely to be formed due to aggregation, which may reduce the surface smoothness of the conductive layer. From this point of view, the _D50 particle size of the conductive inorganic powder (B1) is preferably 0.1 µm or more, more preferably 0.5 µm or more, and particularly preferably 1 µm or more.

The content of the conductive inorganic powder (B1) in the photosensitive conductive paste (B) is suitably 74% by mass or more, preferably 78% by mass or more, more preferably 79% by mass or more, and 80% by mass or more. is more preferable, and 81% by mass or more is particularly preferable. As a result, a dense and thick conductive layer can be formed, and low-resistance electronic components can be manufactured. However, if the concentration of the conductive inorganic powder (B1) is increased too much, the fluidity of the paste will be greatly reduced, making it difficult to uniformly apply the photosensitive conductive paste (B) to the surface of the green sheet. have a nature. Therefore, the content of the conductive inorganic powder (B1) is preferably 90% by mass or less, more preferably 85% by mass or less. It should be noted that the paste containing the conductive inorganic powder (B1) at a high concentration makes it difficult for light to pass through to the inside of the film-like body in the exposure step, so that the fixability of the photocured film to the green sheet decreases. There is a tendency for the development margin to be shortened (exfoliation of the photocured film, etc., tends to occur). However, according to the technology disclosed herein, it is possible to appropriately cause sheet attack and improve the fixability of the photocured film to the green sheet. Even in this case, a sufficiently long development margin can be ensured.

(2-2) Photocurable resin (B2)
The photocurable resin (B2) is an organic compound that is cured by a polymerization reaction, a cross-linking reaction, or the like when irradiated with light (ultraviolet rays). For the photosensitive conductive paste (B) disclosed herein, conventionally known photocurable resins that can be used for photosensitive pastes can be used without particular limitation. For example, the photocurable resin (B2) may be a photocurable polymer having a relatively high molecular weight (e.g., a weight average molecular weight of 6000 or more), or a relatively low molecular weight (e.g., a weight average molecular weight of 6000) photocurable oligomer. If a photocurable polymer is used as the photocurable resin (B2), the fixability of the filmy body to the green sheet before photocuring can be improved. Considering fixability to such a green sheet, the weight average molecular weight Mw of the photocurable resin (B2) is preferably 500 or more, more preferably 750 or more, still more preferably 1000 or more, and particularly preferably 1500 or more. On the other hand, the upper limit of the weight average molecular weight Mw of the photocurable resin (B2) is preferably 60,000 or less, more preferably 50,000 or less, still more preferably 40,000 or less, and particularly preferably 30,000 or less.

A suitable example of the photocurable resin (B2) is a (meth)acrylic resin. Since (meth)acrylic resins are excellent in flexibility and durability after photocuring, peeling and breakage of the photocured film before baking can be suppressed. In addition, "(meth)acrylic resin" is a photocurable resin having a (meth)acryloyl group. Here, "(meth)acryloyl group" means "methacryloyl group (-C(=O)-C( _CH3 )= _CH2 )" and "acryloyl group (-C(=O)-CH= _CH2 )” is a term that includes Preferred examples of the (meth)acrylic resin include homopolymers of alkyl (meth)acrylates and copolymers containing alkyl (meth)acrylates as main monomers and copolymerizable sub-monomers in the main monomers. is mentioned. Specific examples of the homopolymer include polymethyl (meth)acrylate, polyethyl (meth)acrylate, polybutyl (meth)acrylate, and the like. Specific examples of the copolymer include, for example, block copolymers containing, as repeating structural units, a methacrylic acid ester polymer and an acrylic acid ester polymer block. Specific examples of methacrylates include methyl methacrylate, propyl methacrylate, n-butyl methacrylate, and t-butyl methacrylate. Specific examples of acrylic acid esters include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, t-butyl acrylate, and n-hexyl acrylate. In addition, the above-mentioned "(meth)acrylate" is a term including "methacrylate" and "acrylate". Moreover, from the viewpoint of improving photocurability, the (meth)acrylic resin preferably has a (meth)acryloyl group (preferably an acryloyl group) in its side chain. As the (meth)acrylic resin as described above, commercially available products can be used without particular limitation. As such commercially available (meth)acrylic resins, for example, those manufactured by Nippon Kayaku Co., Ltd., Kyoeisha Chemical Co., Ltd., Shin-Nakamura Chemical Co., Ltd., and Toagosei Co., Ltd. can be used.

Moreover, the content of the photocurable resin (B2) in the photosensitive conductive paste (B) is preferably 2% by mass or more, more preferably 4% by mass or more, and particularly preferably 6% by mass or more. This makes it possible to form a photocured film that is properly fixed on the surface of the green sheet with a short exposure time. On the other hand, the upper limit of the content of the photocurable resin (B2) is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less. As a result, it is possible to prevent the light-shielded portion from being photocured in the exposure process, and improve the precision of the photocured film after development.

(2-3) Photopolymerization initiator (B3)
The photopolymerization initiator (B3) is a component that is decomposed by irradiation with light (eg, ultraviolet rays) to generate active species such as radicals and cations, thereby promoting the polymerization reaction of the photocurable resin (B2). Such a photocurable resin (B2) can be used singly or in combination of two or more of conventionally known ones depending on the type of the photocurable resin (B2). Preferred examples of the photopolymerization initiator (B2) include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-( 4-morpholinophenyl)-butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4-diethylthioxanthone, benzophenone etc.

In addition, from the viewpoint of preventing photocuring of the portion shielded by the photomask in the exposure step, the content of the photopolymerization initiator (B3) in the photosensitive conductive paste (B) is preferably 5% by mass or less, and 4% by mass. % or less, more preferably 3 mass % or less, and particularly preferably 2 mass % or less. On the other hand, from the viewpoint of more suitably shortening the exposure time, the content of the photopolymerization initiator (B3) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and 0.5% by mass. The above is more preferable, and 1% by mass or more is particularly preferable.

(2-4) Organic solvent (B4)
As the organic solvent (B4), the same kind as the dispersion medium (A3) of the base-forming paste (A) can be used. That is, the organic solvent (B4) of the photosensitive conductive paste (B) includes alcohol solvents such as terpineol; glycol solvents such as ethylene glycol, propylene glycol and diethylene glycol; dipropylene glycol methyl ether, methyl cellosolve (ethylene glycol monomethyl ether), diethylene glycol dibutyl ether, propylene glycol monophenyl ether, and other ether solvents; glycol ether acetate, 2,2,4-trimethyl-1,3-pentanediol 1-monoisobutyrate, butyl carbitol acetate (diethylene glycol mono butyl ether acetate) and isobornyl acetate; hydrocarbon solvents such as toluene, xylene, naphtha and petroleum hydrocarbons; mineral spirits; As with the binder resin (A2) and the surface treatment agent described above, the specific components of the organic solvent (B4) are not particularly limited as long as the conditions regarding the HSP distance described later are satisfied, and the photosensitive conductive paste ( Conventionally known organic components capable of functioning as the organic solvent of B) can be used without particular limitation. For example, as a commercially available organic solvent, it is sold by Toho Chemical Industry Co., Ltd., Nippon Koryo Chemical Co., Ltd., Nippon Koryo Chemical Co., Ltd., Musashino Chemical Laboratory Co., Ltd., Dow Chemical Japan Co., Ltd., Nippon Terpene Co., Ltd., etc. Organic solvents can be used.

Moreover, the content of the organic solvent (B4) in the photosensitive conductive paste (B) is suitably 10% by mass or more. As a result, it is possible to appropriately generate a sheet attack on the green sheet. Moreover, considering ease of handling of the photosensitive conductive paste (B), the content of the organic solvent (B4) is preferably 11% by mass or more, more preferably 12% by mass or more. On the other hand, considering the denseness of the conductive layer after baking, the upper limit of the content of the organic solvent (B4) is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less.

(2-5) Other additive components In addition, the photosensitive conductive paste (B) contains components other than the above-described components (B1) to (B4) as long as the effects of the technology disclosed herein are not significantly impaired. may contain. The other additive component is not particularly limited, and conventionally known additive components can be used alone or in appropriate combination of two or more. Such other additive components include binder resins, ultraviolet absorbers, polymerization inhibitors, radical scavengers, antioxidants, plasticizers, surfactants, leveling agents, dispersants, antifoaming agents, anti-gelling agents, stabilizers, agents, preservatives and the like. For example, the photosensitive conductive paste (B) may contain the same binder resin as the binder resin (A2) of the paste (A) for base material formation. For example, the content of the binder resin in the photosensitive conductive paste (B) is preferably 8.5% by mass or less, more preferably 8.0% by mass or less, even more preferably 7.5% by mass or less, and 7.0% by mass. % or less is particularly preferred. This can sufficiently ensure the denseness of the conductive layer after firing. On the other hand, the lower limit of the content of the organic binder (B5) may be 0% by mass (not including the binder resin), 2.0% by mass or more, or 3.0% by mass or more. It may be present, and may be 5.0% by mass or more. Thereby, the fixability of the photosensitive conductive paste (B) to the green sheet can be improved more appropriately.

(3) HSP distance of each component The components of each paste have been described above. Then, in the production kit disclosed herein, "HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B)", Each of the "HSP distance between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B)" is adjusted to a predetermined range. It is As a result, it is possible to suitably suppress the generation of residues while ensuring a sufficiently long development margin, so that it is possible to stably manufacture an electronic component having a precise conductive layer. A specific description will be given below.

First, in the production kit disclosed herein, the HSP distance between the binder resin (A2) and the organic solvent (B4) is adjusted to 2.5 or less. As a result, the organic solvent (B4) of the photosensitive conductive paste (B) can sufficiently cause a sheet attack in which the binder resin (A2) of the green sheet (base-forming paste (A)) dissolves. As a result, the fixability of the photocured film to the surface of the green sheet can be improved, and a sufficiently long development margin can be ensured. Incidentally, when the HSP distance between the binder resin (A2) and the organic solvent (B4) is made smaller, the development margin tends to become longer. From this point of view, the HSP distance between the binder resin (A2) and the organic solvent (B4) is preferably 2.3 or less, more preferably 2.2 or less, even more preferably 2.1 or less, and particularly 2.0 or less. preferable.

On the other hand, if the HSP distance between the binder resin (A2) and the organic solvent (B4) is made too small and excessive sheet attack occurs, the fixability of the unexposed portion (uncured film) increases, resulting in development. The generation of residues after treatment may be accelerated. Therefore, in the manufacturing kit disclosed herein, the HSP distance between the binder resin (A2) and the organic solvent (B4) is adjusted to 1.0 or more. From the viewpoint of more appropriately suppressing the generation of residues, the HSP distance between the binder resin (A2) and the organic solvent (B4) is preferably 1.2 or more, more preferably 1.3 or more, and 1.4. More preferably 1.5 or more, particularly preferably 1.5 or more.

Next, in the manufacturing kit disclosed herein, between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) HSP distance of is adjusted to 1.0 or more. This prevents the conductive inorganic powder (B1) from adhering to the surface of the green sheet via the surface treatment agent, thereby more appropriately suppressing the generation of residues. If the HSP distance between the binder resin (A2) and the surface treatment agent of the conductive inorganic powder (B1) is further increased, the generation of residues can be suppressed more favorably. From this point of view, the HSP distance between the binder resin (A2) and the surface treatment agent is preferably 1.2 or more, more preferably 1.3 or more, still more preferably 1.4 or more, and particularly preferably 1.5 or more.

As described above, in the manufacturing kit disclosed herein, the HSP distance between the binder resin (A2) and the organic solvent (B4) is set so that the sheet attack that is compatible with the suppression of the residue and the development margin at a high level is generated. is regulated. Furthermore, in this production kit, a binder resin (A2) and a surface treatment agent for the conductive inorganic powder (B1) are used so as to prevent adhesion between the conductive inorganic powder (B1) and the green sheet via the surface treatment agent. HSP distance between is adjusted. This makes it possible to more appropriately prevent the generation of residues after development processing. As a result, according to the manufacturing kit disclosed herein, it is possible to stably manufacture an electronic component having a precise conductive layer.

Although the technique disclosed herein is not limited, the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) The upper limit of the HSP distance between is preferably 3.5 or less, more preferably 3.0 or less, still more preferably 2.7 or less, and particularly preferably 2.5 or less. Experiments have confirmed that a longer development margin can be ensured by reducing the HSP distance between the binder resin (A2) and the surface treatment agent.

It should be noted that the technique disclosed herein only requires that the HSP distance satisfies the above conditions, and the specific HSP value itself of each component is not particularly limited. For example, the lower limit of the HSP value of the binder resin (A2) of the base-forming paste (A) may be 15 or more, 16 or more, or 17 or more. On the other hand, the upper limit of the HSP value of the binder resin (A2) may be 25 or less, 24 or less, 23 or less, or 22 or less. Similarly, the lower limit of the HSP value of the organic solvent (B4) of the photosensitive conductive paste (B) may be 15 or more, 16 or more, or 17 or more. On the other hand, the upper limit of the HSP value of the organic solvent (B4) may be 25 or less, 24 or less, 23 or less, or 21 or less. The lower limit of the HSP value of the surface treatment agent of the conductive inorganic powder (B1) may be 15 or more, 16 or more, or 17 or more. On the other hand, the upper limit of the HSP value of the surface treatment agent of the conductive inorganic powder (B1) may be 25 or less, 24 or less, 23 or less, or 21 or less. good.

In addition, the "HSP value of the binder resin (A2)" in this specification is based on the fact that the binder resin (A2) is added dropwise to each of a solvent with a high HSP value and a solvent with a low HSP value, and the solvent becomes cloudy. It is a numerical value based on the turbidity titration method for calculating the HSP value. The "HSP value of the organic solvent (B4)" is a value calculated based on the molecular structure of the organic solvent (B4). Then, the "HSP value of the surface treatment agent of the conductive inorganic powder (B1)" is calculated based on the sedimentation rate when the conductive inorganic powder (B1) to which the surface treatment agent is applied is added to the organic solvent. value. As described above, in the technology disclosed herein, the HSP value measurement means differs for each component. The reason is as follows. First, since the binder resin (A2) has a huge molecular structure and it is difficult to calculate the HSP value by calculation based on the molecular structure, it is necessary to use a turbidity titration method to measure the HSP value. On the other hand, in the technique disclosed herein, in order to suppress adhesion between the green sheet and the conductive inorganic powder (B1) via the surface treatment agent, "HSP value of the surface treatment agent of the conductive inorganic powder (B1) ” is controlled. Considering this purpose, it is meaningless to measure the HSP value of the surface treatment agent before it is attached to the conductive inorganic powder (B1), and the surface treatment agent is attached to the surface of the conductive inorganic powder (B1). It is necessary to measure the HSP value of For this reason, in the present specification, based on the sedimentation rate when the conductive inorganic powder (B1) to which the surface treatment agent is added is added to an organic solvent, "HSP value of the surface treatment agent of the conductive inorganic powder (B1) ” is measured.

As described above, each paste used in the production kit disclosed herein includes various surface treatment agents in addition to the binder resin (A2), the organic solvent (B4), and the conductive inorganic powder (B1). of organic components (photocurable resin (B2), etc.). However, the HSP values of such other organic components do not significantly affect the effectiveness of the technology disclosed herein. For example, in the technique disclosed herein, a sufficiently long development margin is ensured by appropriately causing sheet attack in which the binder resin (A2) is dissolved in the organic solvent (B4). In addition, generation of residues is suppressed by suppressing excessive sheet attack and preventing adhesion between the green sheet and the conductive inorganic powder (B1) via the surface treatment agent. Considering these mechanisms of action, it is understood that organic components other than the binder resin (A2), organic solvent (B4) and surface treatment agent do not significantly affect the effect of extending the development margin and the effect of suppressing residue.

2. Electronic Component Manufacturing Method Next, an embodiment of an electronic component manufacturing method using the manufacturing kit disclosed herein will be described. 1 to 3 are cross-sectional views explaining each step of the method for manufacturing an electronic component according to this embodiment. Note that the dimensional relationships (length, width, thickness, etc.) in these drawings do not necessarily reflect the actual dimensional relationships.

(1) Green Sheet Preparing Step In this step, a green sheet is prepared by molding the base material forming paste (A) into a sheet shape. In this step, for example, a green sheet (see FIG. 1) can be formed by applying a paste to the surface of a PET film (thickness of about 0.1 mm) by a doctor blade method. Note that this process is not limited to the procedure described above, and the green sheet 10 can be formed using various methods. Alternatively, a preformed green sheet may be prepared separately.

(2) Film Formation Step In this step, the photosensitive conductive paste (B) is applied to the surface of the green sheet, and the photosensitive conductive paste (B) is dried. As a result, a film-like body 20 is formed on the surface of the green sheet 10, as shown in FIG. The drying temperature in this step is suitable to be about 30° C. to 60° C., and the drying time is suitable to be about 5 minutes to 20 minutes.

Here, in the present embodiment, the HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is adjusted to 2.5 or less. ing. Therefore, when the photosensitive conductive paste (B) is applied to the surface of the green sheet 10, the organic solvent (B4) of the photosensitive conductive paste (B) dissolves into the green sheet 10, and the binder resin (A2 ) is generated by sheet attack. As a result, the binder resin (A2) is distributed across the boundary between the film-like body 20 and the green sheet 10 after drying, so that the fixability of the film-like body 20 to the surface of the green sheet 10 can be improved. .

(3) Exposure Step As shown in FIG. 2, in this step, the film 20 is covered with a photomask M1 having slits M1a of a predetermined pattern, and a portion of the film 20 exposed from the slits M1a is exposed. As a result, the portion shielded from light by the photomask M1 is maintained as the film-like body 20, and the exposed portion immediately below the slit M1a is photocured to become a photocured film 22. FIG. In this exposure process, an exposure machine that emits light rays (typically ultraviolet rays) in a wavelength range of 10 to 500 nm, for example, an ultraviolet irradiation lamp such as a high-pressure mercury lamp, a metal halide lamp, or a xenon lamp can be used.

(4) Development Step In this step, the uncured film 20 shielded by the photomask is removed with a developer. In this step, for example, a developing process is performed in which a developer is sprayed onto the film-like body 20 and the photocured film 22 formed on the surface of the green sheet 10 . The development time (spraying time of the developer) at this time is set to such a time that the unexposed portion of the film 20 is removed and the exposed portion of the photocured film 22 remains. As a result, a photocured film 22 having a predetermined pattern is developed on the surface of the green sheet 10 (see FIG. 3). As the developer, an alkaline aqueous developer or the like can be used. As an example of such an aqueous developer, an aqueous sodium hydroxide solution, an aqueous sodium carbonate solution, or the like can be used. The alkali concentration of these water-based developers may be adjusted to, for example, 0.01 to 0.5% by mass.

Here, in the present embodiment, since the fixability of the photocured film 22 due to sheet attack is improved in the film forming process, peeling of the photocured film 22 during development can be appropriately prevented, and a sufficient length of film can be obtained. A small development margin can be secured. However, if the sheet attack occurs excessively, the fixability of the unexposed portion (film 20) is increased, and the film 20 remains on the surface of the green sheet 10 after development to form a residue. there is a possibility. On the other hand, in the present embodiment, the HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is set to 1.0 or more. It is adjusted to prevent excessive seat attack. Furthermore, when a surface treatment agent is applied to the particle surface of the conductive inorganic powder (B1), the conductive inorganic powder (B1) may adhere to the surface of the green sheet 10 via the surface treatment agent and become a residue. have a nature. On the other hand, in the present embodiment, the HSP distance between the binder resin (A2) and the surface treatment agent of the conductive inorganic powder (B1) is adjusted to 1.0 or more, and the surface treatment that causes residue generation It prevents adhesion of the conductive inorganic powder (B1) through the agent.

(5) Baking Step In this step, the green sheet 10 and the photocured film 22 remaining on the surface of the green sheet 10 are baked. As a result, an electronic component having an insulating inorganic base material and a linear conductive layer formed on the surface of the inorganic base material in a predetermined pattern is manufactured. The sintering temperature (maximum temperature in the sintering treatment) in this step is preferably about 600°C to 1000°C.

As described above, according to the technique disclosed herein, it is possible to suitably suppress the generation of residues while ensuring a sufficiently long development margin, so that it is possible to stably manufacture an electronic component having a precise conductive layer. The manufactured electronic component can be used as, for example, an inductor component, a capacitor component, a multilayer circuit board, or the like. Typical examples of inductor components include high frequency inductors, common mode filters, high frequency circuit inductors (coils), general circuit inductors (coils), high frequency filters, choke coils, and transformers. Further, the shape (structure) of the electronic component is not particularly limited, and may be a surface mounting type, a through-hole mounting type, or the like. Further, the electronic component may be a laminated type in which a plurality of conductive layers are laminated, or may be a thin film type having a single conductive layer.

[Test example]
Test examples relating to the technology disclosed herein will be described below. It should be noted that the following description is not intended to limit the technology disclosed herein to those shown in the test examples.

1. Sample preparation In this test, each of "HSP value of binder resin (A2)", "HSP value of organic solvent (B4)", and "HSP value of surface treatment agent of conductive inorganic powder (B1)" was measured. Twenty-six different electronic component manufacturing kits (Test Examples 1 to 26) were prepared. The procedure for preparing each test example is described below.

(1) Preparation of base material forming paste (A) First, alumina powder ( _D50 particle size: 3 μm) was prepared as the insulating inorganic powder (A1), and the content was 30% by mass with respect to 100% by mass of the paste. Weighed so that Next, three types of binder resins (resins a to c) shown in Table 1 below were prepared, and in each of Test Examples 1 to 26, one of the following resins a to c was used as the binder resin (A2). did. The binder resin (A2) used in each sample is shown in Table 4 below. The content of the binder resin (A2) was uniformed to 10% by mass in all of Test Examples 1-26. Then, the insulating inorganic powder (A1) and the binder resin (A2) were mixed and subjected to ultrasonic dispersion for 1 hour to prepare a substrate forming paste (A).

(2) Preparation of photosensitive conductive paste (B) First, silver powder ( _D50 particle size: 2.5 μm) to which a surface treatment agent is applied is prepared as a conductive inorganic powder (B1), and the paste is 100% by mass. It was weighed so that the content of 80% by mass. In this test, three kinds of silver powders (silver powders a to c) with different types of surface treatment agents were prepared (see Table 2). Next, a (meth)acrylic resin (bifunctional acrylate) was prepared as the photocurable resin (B2) and weighed so that the content was 4.7% by mass. In addition, 2,4,6-trimethylbenzoyldiphenylphosphine oxide was prepared as a photopolymerization initiator (B3) and weighed so that the content was 0.12% by mass. In this test, six types of organic solvents (solvents a to f) shown in Table 3 below were prepared as the organic solvent (B4), and the total content of the organic solvent (B4) was 13.3% by mass. Any of the solvents a to f were used alone or in admixture, as appropriate. Furthermore, a cellulose resin (methylcellulose-based water-soluble resin) was prepared as a binder resin and weighed so that the content thereof was 1.9% by mass. Then, a photosensitive conductive paste (B) was prepared by mixing the components described above and performing ultrasonic dispersion for 1 hour. The conductive inorganic powder (B1) and the organic solvent (B4) used in each test example are shown in Table 4 below.

2. Evaluation test A conductive layer was formed on the surface of the inorganic substrate using 26 types of manufacturing kits (Test Examples 1 to 26) that combined the base-forming paste (A) and the photosensitive conductive paste (B). An electronic component was produced. Specifically, first, the substrate-forming paste (A) was molded into a sheet to prepare a green sheet of width 50 mm×length 75 mm×thickness 0.2 mm. Then, using screen printing, a photosensitive conductive paste was applied to the surface of the green sheet in a size of 20 mm wide×20 mm long×32 μm thick, and then dried at 55° C. for 10 minutes to form a film. formed. Then, a photomask having slits of a predetermined pattern was placed on the filmy body, and light was irradiated under the conditions of an illuminance of 30 mW/cm ² and an exposure amount of 300 mJ/cm ² . It was exposed to light to form a photocured film. In this test, a photomask having slits with L/S (line/space) set to 15 μm/15 μm was used.

Next, a developing process was performed to remove the film-like material on the green sheet using a developing solution. In this step, the developer (0.1% by mass Na ₂ CO ₃ aqueous solution) was continuously sprayed onto the film-like material on the green sheet for a predetermined development time. Specifically, after measuring the developing time (break point) at which the film-like material on the green sheet was completely removed, the developing treatment was continued until peeling or disconnection occurred in the photocured film. Then, the time from the break point to the point at which peeling or disconnection was confirmed was regarded as a "development margin", and the length of the development margin was evaluated. The evaluation results are shown in the column of "development margin evaluation" in Table 4. The evaluation criteria for the "development margin evaluation" in Table 4 are as follows.
"Poor": Peeling or the like occurred in the photocured film within 3 seconds from the break point.
"Fair": Peeling or the like occurred in the photocured film within 3 seconds or more and less than 7 seconds from the break point.
"◯": No peeling or the like occurred in the photocured film even after 7 seconds or more had passed from the break point.

Next, in each test example, a sample was produced in which development processing was completed within the range of the development margin described above. The sample was then observed with an optical microscope to count the number of residues adhering to the spaces between the adjacent photocured films. Then, the average number of residues in the three fields of view was calculated, and the residue suppression performance in each test example was evaluated based on the calculation results. The results are shown in the column of "Residue evaluation" in Table 4. In addition, the evaluation criteria in this evaluation are as follows.
"x": The average number of residues was 4 or more.
"◯": The average number of residues was 3 or less.

As shown in Table 4 above, as a result of the development margin evaluation, in Test Examples 1 to 3, 5 to 7, 9 to 11, 13 to 15, 17, 18, and 20 to 25, a development margin of 3 seconds or more was secured. I was able to From this, by setting the HSP distance between the organic solvent (B4) of the photosensitive conductive paste (B) and the binder resin (A2) of the base material forming paste (A) to 2.5 or less, a sufficient length It was found that a development margin of . It is presumed that this is because the binder resin (A2) is more easily dissolved in the organic solvent (B4), and as a result, sheet attack on the green sheet occurs appropriately. Further, as a result of comparing Test Examples 10 and 13, it was found that a longer development margin can be secured by setting the HSP distance between the surface treatment agent of the conductive inorganic powder (B1) and the binder resin (A2) to 3.5 or less. was confirmed.

Next, as a result of residue evaluation, in Test Examples 2, 4 to 6, 8, 10, 12 to 14, 16, 17, 19 to 24, and 26, the average number of residues after development was suppressed to 3 or less. . From this, the HSP distance between the organic solvent (B4) and the binder resin (A2) is set to 1.0 or more, and the HSP distance between the surface treatment agent of the conductive inorganic powder (B1) and the binder resin (A2) is set to It was found that the generation of residue can be suitably suppressed by setting the ratio to 1.0 or more. This is to prevent excessive sheet attack due to the HSP distance between the organic solvent (B4) and the binder resin (A2) being too close, and then apply the conductive inorganic powder ( It is presumed that it became possible to prevent the adhesion of silver powder).

In addition, from the results of this test, in order to properly exhibit the effect of the technology disclosed herein, the HSP distance between the organic solvent (B4) and the binder resin (A2), and the surface treatment agent and the binder resin The HSP distance between (A2) may be appropriately adjusted, and the specific types and structures of the binder resin (A2), the organic solvent (B4) and the surface treatment agent are the effects of the technology disclosed here. was found to have no significant effect on

Although the present invention has been described in detail above, these are merely examples, and the present invention can be modified in various ways without departing from the scope of the invention.

REFERENCE SIGNS LIST 10 green sheet 20 filmy body 22 photocured film

Claims (8)

An electronic component manufacturing kit comprising a base-forming paste (A) for forming an insulating inorganic base and a photosensitive conductive paste (B) for forming a conductive layer on the surface of the inorganic base, ,
The base material forming paste (A) is
an insulating inorganic powder (A1);
including a binder resin (A2),
The photosensitive conductive paste (B) is
A conductive inorganic powder (B1) having a surface treatment agent attached to the particle surface;
A photocurable resin (B2), a photopolymerization initiator (B3),
and an organic solvent (B4),
The HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is 1.0 or more and 2.5 or less ,And,
The HSP distance between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) is 1.0 or more. A kit for manufacturing electronic components. The HSP distance between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) is 3.5 or less. The electronic component manufacturing kit according to claim 1, wherein 3. The electronic component manufacturing kit according to claim 1, wherein the binder resin (A2) has an HSP value of 17.0 to 22.0. The electronic component manufacturing kit according to any one of claims 1 to 3, wherein the organic solvent (B4) has an HSP value of 17.0 to 21.0. The electronic component manufacturing kit according to any one of claims 1 to 4, wherein the surface treatment agent for the conductive inorganic powder (B1) has an HSP value of 17.5 to 21.0. The electronic component manufacturing kit according to any one of claims 1 to 5, wherein the conductive inorganic powder (B1) contains silver-based particles. A photosensitive conductive paste used in the electronic component manufacturing kit according to any one of claims 1 to 6,
The conductive inorganic powder (B1) having a surface treatment agent attached to the surface, the photocurable resin (B2), the photopolymerization initiator (B3), and the organic solvent (B4),
The HSP distance between the binder resin (A2) of the base material forming paste (A) and the organic solvent (B4) of the photosensitive conductive paste (B) is 1.0 or more and 2.5 or less ,And,
The HSP distance between the binder resin (A2) of the base material forming paste (A) and the surface treatment agent of the conductive inorganic powder (B1) of the photosensitive conductive paste (B) is 1.0 or more. , a photosensitive conductive paste. A method for manufacturing an electronic component using the electronic component manufacturing kit according to any one of claims 1 to 6,
A green sheet preparation step of preparing a green sheet obtained by molding the base material forming paste (A) into a sheet shape;
a filmy body forming step of applying the photosensitive conductive paste (B) to the surface of the green sheet and drying the photosensitive conductive paste (B) to form a filmy body;
an exposure step of covering the filmy body with a photomask having slits of a predetermined pattern, and irradiating a part of the filmy body exposed from the slits with light to form a photocured film;
a developing step of removing the uncured film-like body shielded by the photomask with a developer;
A method of manufacturing an electronic component, comprising a baking step of baking the green sheet and the photocured film remaining on the surface of the green sheet.

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