CN114096919A

CN114096919A - Method for producing photosensitive composition, paste-like photosensitive composition, method for producing electronic component, and device for determining mixing ratio of organic component in photosensitive composition, and computer program

Info

Publication number: CN114096919A
Application number: CN202080049490.8A
Authority: CN
Inventors: 佐合佑一朗; 长江省吾
Original assignee: Noritake Co Ltd
Current assignee: Noritake Co Ltd
Priority date: 2019-07-10
Filing date: 2020-05-28
Publication date: 2022-02-25
Also published as: JP2021015155A; WO2021005910A1; JP6694099B1; KR20220034178A; TW202104867A

Abstract

According to the present invention, there is provided a method for producing a photosensitive composition, comprising the steps of: a step of measuring the particle diameter of the conductive powder to obtain an actual measurement value (step S1); comparing the measured value with a 1 st correlation expression of an arbitrary factor that varies in relation to the displacement of the particle diameter of the conductive powder, and confirming a predicted deviation value of the factor from a predetermined target level (step S2); and a step of determining the blending ratio of the organic component so as to eliminate the predicted deviation value, based on the factor in the 1 st correlation formula and the 2 nd correlation formula of an arbitrary organic component contained in the photosensitive composition and having a variation in the blending ratio related to a variation in the factor (step S3).

Description

Method for producing photosensitive composition, paste-like photosensitive composition, method for producing electronic component, and device for determining mixing ratio of organic component in photosensitive composition, and computer program

Technical Field

The present invention relates to a method for producing a photosensitive composition, a paste-like photosensitive composition, a method for producing an electronic component, and a device for determining a mixing ratio of organic components in a photosensitive composition, and a computer program.

It should be noted that the present application claims priority based on japanese patent application No. 2019-128628, which is applied on 7/10/2019, and the entire contents of the application are incorporated by reference into the present specification.

Background

In the manufacture of electronic components such as inductors, the following methods are known: a conductive layer is formed on a substrate by photolithography using a photosensitive composition containing a conductive powder, a photopolymerizable resin, and a photopolymerization initiator (see, for example, patent documents 1 and 2). In the above method, first, a photosensitive composition is applied to a substrate and dried to form a conductive film (a conductive film forming step). Next, a photomask having a predetermined opening pattern is covered on the molded conductive film, and the conductive film is exposed through the photomask (exposure step). Thereby, the exposed portion of the conductive film is photo-cured. Next, the unexposed portion shielded from light by the photomask is etched and removed in a developing solution (developing step). Then, the conductive film to be a desired pattern is fired to be sintered on the substrate (firing step). According to the photolithography method including the above steps, a conductive layer can be formed more finely than in conventional printing methods.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5163687

Patent document 2: international publication No. 2015/122345

Disclosure of Invention

However, in recent years, the miniaturization and high performance of various electronic devices have been rapidly advanced, and further miniaturization and high density have been demanded for electronic components mounted on the electronic devices. Accordingly, in the production of electronic components such as a laminated chip inductor, the conductive layer is required to have a low resistance and to have a small line (narrow size). More specifically, the line width of the wiring constituting the conductive layer and the space between adjacent wirings (line width/line distance: L/S) are required to be reduced to 30 μm/30 μm or less, and further to 20 μm/20 μm or less. If the L/S of the conductive layer is small, the adjacent wirings are connected to each other by only a slight increase in the line width of the wirings, and short-circuit failure occurs, or conversely, peeling or disconnection easily occurs by only a slight decrease in the line width of the wirings. Therefore, for example, in an electronic device such as a laminated chip inductor, if the line width fluctuation is large, the product characteristics are adversely affected, and the yield is lowered. Therefore, from the viewpoint of mass production, it is necessary to suppress the fluctuation of the line width of the conductive layer after baking by suppressing the fluctuation of the line width of the conductive layer after development to be low, and to form fine line-shaped wiring in an electronic component with good reproducibility.

The present invention has been made in view of the above-described problems, and an object thereof is to provide: a photosensitive composition capable of forming fine wiring with a desired line width with good reproducibility. In addition, another object of the present invention is to provide: a method of manufacturing an electronic component and an electronic component. In addition, another object of the present invention is to provide: an apparatus for determining the mixing ratio of organic components in a photosensitive composition and a computer program.

The present inventors have conducted intensive studies on the respective components of the photosensitive composition, and as a result, newly determined that the particle diameter of the conductive powder is 1 important factor for determining the line width after development. That is, fig. 1 (a) is a schematic side view showing the appearance of the exposure step when the conductive powder 1A having a relatively large particle diameter is used. As shown in fig. 1 (a), if the particle diameter of the conductive powder 1A is large, light that has penetrated from the opening of the photomask into the interior of the conductive film is reflected on the surface of the conductive powder 1A, and light scattering tends to occur. Therefore, light becomes easy to spread in the horizontal direction of the conductive film. As a result, light also reaches the periphery of the opening of the photomask (the portion shielded from light by the photomask), and the line width tends to be larger than the opening width of the photomask. On the other hand, fig. 1 (B) is a schematic side view showing the appearance of the exposure step when the conductive powder 1B having a relatively small particle diameter is used. As shown in fig. 1 (B), if the particle diameter of the conductive powder 1B is small, light that has penetrated from the opening of the photomask into the interior of the conductive film is less likely to be reflected on the surface of the conductive powder 1B, and scattering of light is suppressed. Therefore, light is less likely to diffuse in the horizontal direction of the conductive film, and the line width is relatively easy to be smaller than that in fig. 1 (a). From this, it can be said that in order to stabilize the line width, it is desirable to highly control the particle diameter of the conductive powder used.

However, according to the investigation by the present inventors, the particle diameter varies slightly depending on the production lot (product unit) of the conductive powder. For example, the inventors believe that: several batches of conductive powder having an average particle size (nominal value) of 2.9 μm were purchased, and the average particle size was actually measured, and as a result, the average particle size (actual measurement value) was varied by about ± 0.4 μm from the nominal value. The variation is considered to be caused by fluctuation in the production process. Therefore, in this state, it is expected that the line width fluctuates due to the fluctuation of the average particle diameter (actually measured value) of the conductive powder. Therefore, the present inventors considered whether it is possible to buffer the fluctuation of the line width that may occur due to the variation between the production lots of the conductive powder when producing the photosensitive composition. Further studies have been repeated, and as a result, the present invention has been conceived.

According to the present invention, there is provided a method for producing a photosensitive composition containing a conductive powder at a predetermined compounding ratio. The manufacturing method comprises the following steps: a step of measuring the particle diameter of the conductive powder to obtain an actual measurement value; comparing the measured value with a previously prepared 1 st correlation formula, that is, a 1 st correlation formula of the particle diameter of the conductive powder and an arbitrary factor which fluctuates in association with displacement of the particle diameter and is caused by light absorption or light curing of the conductive film, and confirming a predicted deviation value of the factor from a predetermined target level; and determining the blending ratio of the organic component so as to eliminate the predicted deviation value based on a previously prepared 2 nd correlation formula, that is, a factor in the 1 st correlation formula and a 2 nd correlation formula of an arbitrary organic component contained in the photosensitive composition and having a variation in the blending ratio related to a variation in the factor.

In the above-described production method, the particle size of the conductive powder used in producing the photosensitive composition is measured in advance, and a deviation from a target level is simulated. Then, based on the results of the simulation, the compounding ratio of the organic ingredients was determined in such a manner that the prediction bias value was eliminated. Thus, the influence of variations between production lots of the conductive powder is reduced, and fluctuations in line width due to differences between production lots of the conductive powder can be suppressed. Therefore, it is possible to provide a photosensitive composition which can stably form a desired line width without managing the particle diameter of the conductive powder so high, for example, even if the production lot of the purchased conductive powder is switched in the middle. This improves yield, mass productivity, and productivity.

In a preferred embodiment disclosed herein, the organic component is an organic component for adjusting at least one of light absorption and photopolymerization of the photosensitive composition. The organic component may be at least one of a photopolymerization initiator, a light absorber, and a polymerization inhibitor. The organic component may be a photopolymerization initiator. Thus, for example, the effect of the technology disclosed herein can be exhibited in the case where the compounding ratio of the photocurable component (component cured by polymerization, for example, photocurable compound) in the photosensitive composition is stabilized and the properties of the conductive film, for example, the viscosity to the substrate, are maintained high as a whole.

In a preferred embodiment disclosed herein, the factor in the above-mentioned correlation 1 is a line width, a film thickness, an electrode cross-sectional area, a curing shrinkage ratio, or a resistance value of the conductive film. The factor in the above correlation 1 may be a line width.

In a preferred embodiment disclosed herein, the 2 nd correlation equation is expressed as a linear function. Since 2 variables in the linear function are in a proportional relationship, the compounding ratio can be calculated easily.

In a preferred embodiment disclosed herein, the conductive powder contains silver-based particles. This can realize a conductive layer having excellent balance between cost and low resistance.

In a preferred embodiment disclosed herein, the 1 st conductive powder is core-shell particles including a metal material serving as a core and a ceramic material covering at least a part of a surface of the core. This can improve the stability of the conductive powder in the photosensitive composition more favorably, and can realize a conductive layer having high durability. In addition, for example, in the application of forming a conductive layer on a ceramic base material (ceramic base material) to manufacture a ceramic electronic component, the integrity with the ceramic base material can be improved.

Further, according to the present invention, there is provided a method for manufacturing an electronic component, comprising the steps of: the photosensitive composition is applied to a substrate, photocured, etched, and then baked to form a conductive layer including a baked body of the photosensitive composition. According to this manufacturing method, a small-sized and/or high-density electronic component provided with a conductive layer can be suitably manufactured.

Further, according to the present invention, there is provided an apparatus for determining a compounding ratio of an organic component to a photosensitive composition containing a conductive powder at a predetermined compounding ratio. The compounding ratio determining apparatus includes: an input unit for receiving user input and inputting the type of the conductive powder used and the measured value of the particle size; a storage unit that stores a previously prepared 1 st correlation formula, that is, a 1 st correlation formula in which the particle diameter of the conductive powder and an arbitrary factor that fluctuates in association with a shift in the particle diameter due to a fluctuation caused by light absorption or light curing of a conductive film, and a previously prepared 2 nd correlation formula, that is, a factor in the 1 st correlation formula and an arbitrary organic component that is contained in the photosensitive composition and in which a fluctuation in a compounding ratio and a fluctuation in the factor are associated; a 1 st calculation unit that calculates a predicted deviation value of a factor in the 1 st correlation equation from a predetermined target level from the measured value input by the input unit based on the 1 st correlation equation; and a 2 nd calculating unit that calculates a blending ratio of the organic component in the 2 nd correlation equation from which the prediction bias value is eliminated, based on the 2 nd correlation equation. This prevents calculation errors, and allows the operator who is not familiar with the work, for example, to easily determine the mixing ratio of the organic component.

Further, according to the present invention, there is provided a computer program configured to cause a computer to function as the compounding ratio determination device. This prevents calculation errors, and allows an operator who is not familiar with the work, for example, to easily determine the mixing ratio of the organic components.

Further, according to the present invention, there is provided an electronic component comprising a conductive layer containing a baked body of the photosensitive composition. According to the photosensitive composition, a conductive layer having a fine line-shaped wiring can be stably realized. Therefore, according to the photosensitive composition, a small-sized and/or high-density electronic component provided with a conductive layer can be suitably realized.

Further, according to the present invention, there is provided a paste-like photosensitive composition, wherein the photosensitive composition contains an organic dispersion medium. By preparing the photosensitive composition into a paste, the photosensitive composition can be easily supplied to a desired position on a substrate in a desired form by means of, for example, coating, printing, or the like.

Drawings

Fig. 1 is a schematic side view of a conductive film, where (a) is a side view when a conductive powder having a large average particle diameter is used, and (B) is a side view when a conductive powder having a small average particle diameter is used.

Fig. 2 is a flow chart of a manufacturing method according to an embodiment of the invention.

Fig. 3 is a cross-sectional view schematically showing the structure of the stacked-chip inductor.

Fig. 4 is a functional block diagram of the compounding ratio determining apparatus.

Fig. 5 shows an example of the correlation expression 1 in example 1.

Fig. 6 shows an example of the 2 nd correlation formula of photopolymerization initiators.

Fig. 7 is a graph comparing actual line widths.

Fig. 8 shows an example of the correlation expression 1 in example 2.

Fig. 9 shows an example of the correlation expression 1 in example 2.

Fig. 10 shows an example of the 2 nd correlation of the ultraviolet absorber.

FIG. 11 shows an example of the 2 nd correlation of the photopolymerization inhibitor.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and matters necessary for carrying out the present invention (for example, a method for forming a conductive film, a conductive layer, a method for manufacturing an electronic component, and the like) can be understood based on technical contents demonstrated in the present specification and general technical common knowledge of those skilled in the art in the field. The present invention can be implemented based on the contents disclosed in the present specification and the common technical knowledge in the field.

In the present specification, the "conductive film" refers to a film-like body (dried product) obtained by drying a photosensitive composition at a temperature of not more than the boiling point of an organic component (substantially not more than 200 ℃, for example, not more than 100 ℃). The conductive film includes the whole of the unfired (before firing) film. The conductive film may be an uncured product before photocuring or a cured product after photocuring. In the present specification, the "conductive layer" refers to a sintered body (fired product) obtained by firing a photosensitive composition at a temperature equal to or higher than the firing temperature of the conductive powder. The conductive layer includes a wiring (linear body), a wiring pattern, and a solid pattern. In addition, the expression "a to B" indicating a range in the present specification includes the meaning of a being higher than and lower than B, "preferably being larger than a" and "preferably being smaller than B".

Method for producing photosensitive composition

In the present embodiment, a description will be given of a manufacturing method in which a factor of a target level is a line width (a line width is targeted) particularly in the context of a line width which is important as a required characteristic. That is, in the present embodiment, the predetermined target level is represented by "target line width", and the predicted deviation value is represented by "predicted deviation width". However, as described later, the factor of the target level is not limited to the line width as long as it is caused by the light absorption degree and the light curing degree of the conductive film.

Fig. 2 is a flowchart of the manufacturing method of the present embodiment. The production method disclosed herein is a method for producing a photosensitive composition containing a conductive powder at a predetermined compounding ratio. In this embodiment, the manufacturing method includes the steps of: (step S1) a step of measuring the average particle diameter; (step S2) a confirmation step of predicting the deviation width; (step S3) a step of determining the mixing ratio of organic components; (step S4) a step of preparing a photosensitive composition. Hereinafter, the respective steps will be described in order.

< (step S1) procedure for measuring average particle diameter

In this step, first, a conductive powder used for producing a photosensitive composition is prepared. The conductive powder is a component for imparting conductivity to the conductive layer. The conductive powder may be commercially available or may be prepared by a conventionally known method. The kind of the conductive powder is not particularly limited, and may be used alone by 1 kind or in an appropriate combination of 2 or more kinds depending on the application, for example, from those known in the art.

Examples of the conductive powder include simple substances of metals such as gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), aluminum (Al), nickel (Ni), ruthenium (Ru), rhodium (Rh), tungsten (W), iridium (Ir), and osmium (Os), and mixtures and alloys thereof. Examples of the alloy include silver alloys such as silver-palladium (Ag-Pd), silver-platinum (Ag-Pt), and silver-copper (Ag-Cu). In one preferred embodiment, the conductive powder contains silver-based particles. Silver is relatively inexpensive and has high electrical conductivity. Therefore, when the conductive powder contains silver particles, a conductive layer having excellent balance between cost and low resistance can be realized. In the present specification, "silver-based particles" include all the silver-containing components. Examples of the silver-based particles include a simple substance of silver, the silver alloy, core-shell particles having a silver-based particle as a core, and core-shell particles of silver-ceramic, for example.

The conductive powder may have an organic surface treatment agent attached to its surface. The organic surface treatment agent can be used for the purpose of, for example, improving dispersibility of the conductive powder in the photosensitive composition, improving affinity of the conductive powder with other components, and preventing surface oxidation of a metal constituting the conductive powder. Examples of the organic surface treatment agent include fatty acids such as carboxylic acids, and benzotriazole compounds.

In one suitable embodiment, the conductive powder comprises core-shell particles of a metal-ceramic. The metal-ceramic core-shell particles have: a core portion comprising a metallic material; and a covering portion that includes a ceramic material and covers at least a part of a surface of the core portion. The cover is typically constructed of a plurality of fine ceramic particles. The average particle diameter of the ceramic particles constituting the covering part is typically smaller than the average particle diameter of the metal material constituting the core part, and may be, for example, about 1/1000 to 1/2, and further about 1/100 to 1/10 of the average particle diameter of the metal material. The ceramic material is excellent in chemical stability, heat resistance and durability. Therefore, by adopting the form of the metal-ceramic core-shell particles, the stability of the conductive powder in the photosensitive composition can be more improved, and a conductive layer with high durability can be realized. In addition, for example, in the application of forming a conductive layer on a ceramic substrate to manufacture a ceramic electronic component, the integrity with the ceramic substrate can be improved, and peeling and disconnection of the conductive layer after firing can be suitably suppressed.

The ceramic material constituting the coating layer of the core-shell particles is not particularly limited, and examples thereof include: oxide-based materials such as zirconium oxide (zirconia), magnesium oxide (magnesia), aluminum oxide (alumina), silicon oxide (silica), titanium oxide (titania), cerium oxide (ceria), yttrium oxide (yttria), and barium titanate; composite oxide-based materials such as cordierite (cordierite), mullite (mullite), forsterite (forsterite), steatite (steatite), silicoaluminophosphate (sialon), zircon (zirconia), and ferrite (ferrite); nitride-based materials such as silicon nitride (sic) and aluminum nitride (aluminum nitride); carbide-based materials such as silicon carbide (silicon carbide); hydroxide-based materials such as hydroxyapatite (hydroxyapatite); and the like. For example, in the application of forming a conductive layer on a ceramic substrate to produce a ceramic electronic component, a ceramic material that is the same as or has excellent affinity with the ceramic substrate is preferable. The content ratio of the ceramic material in the core-shell particles is not particularly limited, and may be, for example, 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the metal material in the core portion.

When a commercially available conductive powder is used, the average particle diameter (nominal value) of the conductive powder is preferably approximately 0.1 to 10 μm in balance with exposure performance (for example, light absorbance and light curing degree). By setting the average particle diameter (nominal value) in the above range, a fine wire-shaped wiring can be further stably formed. From the viewpoint of suppressing aggregation in the photosensitive composition and improving the storage stability of the photosensitive composition, the average particle diameter (nominal value, for example, a value measured by a laser diffraction/scattering method, SEM observation, or the like) of the conductive powder may be, for example, 0.5 μm or more, 1 μm or more, 1.5 μm or more, or 2 μm or more. From the viewpoint of improving the thin line formability, advancing the densification of the conductive layer, and lowering the resistance, the average particle diameter (nominal value) of the conductive powder may be, for example, 5 μm or less, 4.5 μm or less, or 4 μm or less.

The conductive powder is typically, but not limited to, substantially spherical with an average aspect ratio of substantially 1 to 2, preferably 1 to 1.5, for example, 1 to 1.3. This can realize more stable exposure performance. In the present specification, the "average aspect ratio" refers to an arithmetic average value (major axis/minor axis ratio) of aspect ratios calculated from an observed image obtained by observing a plurality of conductive particles constituting a conductive powder with an electron microscope. In the present specification, "spherical" refers to a form that is considered as a substantially spherical body (sphere) as a whole, and may include an elliptical shape, a polyhedral shape, a disk spherical shape, and the like.

The conductive powder is not particularly limited, and is prepared in accordance with JIS Z8781: l of 2013^*a^*b^*Luminance L in the chromaticity system^*May be 50 or more. Thus, light can stably reach the deep part of the uncured conductive film during exposure, and a conductive layer having a thickness of, for example, 5 μm or more, and further 10 μm or more can be stably formed. From the above viewpoint, the brightness L of the conductive powder^*May be substantially 55 or more, for example 60 or more. Note that the luminance L is^*The measurement of (b) can be performed, for example, according to JIS Z8722: the optical spectrometer of 2009.

Next, in this step, the average particle diameter of the conductive powder to be used is measured. The method, apparatus, and conditions for measuring the average particle diameter and the conditions for analyzing the measurement results may be the same as those for calculating the correlation expression 1 described later. This improves the prediction accuracy in the step of confirming the prediction variation width (step S2), which will be described later. In one example, the particle size distribution is measured by a particle size distribution measuring apparatus based on a laser diffraction/scattering method. For example, the particle size range of approximately 0.02 to 2800 μm can be measured by using Microtrac MT-3000II series manufactured by Microtrac BEL. The volume-based particle size distribution of the conductive powder can be obtained by particle size distribution measurement. In the particle size distribution, the particle size corresponding to a cumulative value of 50% from the side where the particle size is small (D50 particle size) is defined as the "average particle size (measured value)". As described above, the average particle diameter (measured value) of the conductive powder used in the production of the photosensitive composition was obtained.

< (step S2) confirmation step of prediction deviation width

In this step, first, the 1 st correlation formula is prepared. For example, the 1 st correlation formula is prepared in advance according to the type of the conductive powder (for example, according to the product name). Correlation coefficient R of 1 st correlation equation²It may be substantially 0.85 or more, preferably 0.9 or more, for example 0.92 or more. The 1 st correlation equation can be prepared as follows, for example.

Namely, a headFirst, a plurality of kinds of conductive powders having different production lots and/or different average particle diameters (nominal values) are prepared. In this case, the metal species, average aspect ratio, and luminance L of the conductive powder, which can greatly affect physical properties other than the particle diameters of the plurality of types of conductive powder, for example, exposure performance (for example, light absorbance and light curing degree)^*And the like, thereby eliminating the deviation other than the particle size and clearly evaluating the influence of the particle size itself. Next, the average particle diameters of the plurality of types of prepared conductive powders were individually measured. The average particle diameter can be measured by a conventionally known measurement method. For example, the particle size distribution can be measured by a particle size distribution measuring apparatus based on a laser diffraction/scattering method.

Subsequently, a plurality of kinds of conductive powders each having an actually measured average particle diameter were used to prepare a photosensitive composition. For example, first, a predetermined carrier (vehicle) containing an organic component is prepared, and a photosensitive composition is prepared by dispersing a conductive powder therein. Thus, a plurality of photosensitive compositions having a uniform mixing ratio of the components other than the conductive powder and different types of only the conductive powder are prepared. Subsequently, the prepared photosensitive compositions were applied to substrates, respectively, and photocured and etched. Thereby, a fine wire-shaped wiring is formed.

Then, the wiring on the substrate is observed, and the line width of the wiring is measured from the obtained observation image. For observation of the wiring, for example, a laser microscope can be used. At this time, the line width is measured for a plurality of visual fields, and the arithmetic average value thereof is taken as the actual line width (actual line width). Then, for example, data is plotted in a graph in which the average particle diameter (measured value) of the conductive powder is plotted on the horizontal axis X and the "average particle diameter (measured value) X — actual line width Y" of the actual line width is plotted on the vertical axis Y. From this graph, a correlation between the average particle diameter (measured value) and the actual line width is calculated. Thus, the 1 st correlation formula is prepared.

In this step, the actual measurement value obtained in step S1 is compared with the 1 st correlation formula for the same type of conductive powder. Then, a deviation width (predicted deviation width) assumed with respect to a predetermined target line width is confirmed. For example, first, the actual measurement value obtained in step S1 is interpolated into a correlation expression between the average particle diameter (actual measurement value) and the actual line width, and an expected line width is calculated. Then, the difference between the expected line width and the desired target line width is calculated as a predicted variation width. The target line width may be arbitrarily set. Thus, the prediction error width is confirmed.

< (step S3) organic component compounding ratio determining Process

In this step, first, the 2 nd correlation formula is prepared. For example, the 2 nd correlation formula is prepared in advance according to the type of the conductive powder (for example, according to the product name). Correlation coefficient R of 2 nd correlation formula²It may be substantially 0.85 or more, preferably 0.9 or more, for example 0.92 or more. The 2 nd correlation equation may be represented by a linear function. In the first order function, 2 variables are in proportional relationship. Therefore, the mixing ratio can be calculated easily. The 2 nd correlation equation may be prepared as follows, for example. That is, first, at least one of the organic components used in the production of the photosensitive composition is prepared. For example, at least one of the organic components contained in the carrier used for calculating the 1 st correlation formula is prepared. The number of the organic components to be prepared may be 1, for example, 2 or more.

The organic component to be prepared at this time may include, but is not particularly limited to: a component that affects the curing rate of the photosensitive composition, for example, an organic component (curing rate adjuster) for adjusting at least one of the light absorptivity and the photopolymerization of the photosensitive composition other than the organic binder and the photocurable compound. The prepared organic components may include, for example: (A) at least one of a photopolymerization initiator, (B) a sensitizer, (C) a light absorber, and (D) a polymerization inhibitor. The photopolymerization initiator system may include at least one of (a) a photopolymerization initiator and (B) a sensitizer. The organic component to be prepared may be, for example, the 1 st component having the highest compounding ratio among the components (a) to (D) in the carrier, and may further include the 2 nd component having the second highest compounding ratio.

(A) The photopolymerization initiator is a component that decomposes by irradiation with light to generate an active material such as a radical or cation, and causes a polymerization reaction of the photocurable component to proceed. The photopolymerization initiator is a component for adjusting the photopolymerization property of the photosensitive composition (specifically, accelerating the polymerization reaction). The photopolymerization initiator may be used alone in 1 kind or in an appropriate combination of 2 or more kinds depending on the kind of the photocurable component, for example, from those known in the art. The photopolymerization initiator may be a photo radical polymerization initiator, a photo cation polymerization initiator, or a photo anion polymerization initiator. The photo radical polymerization initiator is particularly preferable in that the reaction speed is high and curing by heat is not required. Typical examples thereof include benzoin-based photopolymerization initiator, α -hydroxyacetophenone-based photopolymerization initiator, α -aminoalkylphenone-based photopolymerization initiator, benzyl ketal-based photopolymerization initiator, α -hydroxyacetophenone-based photopolymerization initiator, α -aminoacetophenone-based photopolymerization initiator, acylphosphine oxide-based photopolymerization initiator, titanocene-based photopolymerization initiator, O-acyloxime-based photopolymerization initiator, oxime ester-based photopolymerization initiator, benzophenone-based photopolymerization initiator, acridine-based photopolymerization initiator, and the like.

(B) A sensitizer (also referred to as an accelerator, a reaction accelerator, or the like) is a component that transfers energy obtained by absorbing light to a photocurable component to accelerate a polymerization reaction of the photocurable component. The sensitizer is a component for adjusting the photopolymerization property (specifically, accelerating the polymerization reaction) of the photosensitive composition. As the sensitizer, conventionally known ones can be used in a single type or in a suitable combination of 2 or more types depending on, for example, the wavelength of light to be irradiated. Typical examples thereof include anthracene-based sensitizers, aromatic ketone-based sensitizers, biphenyl-based sensitizers, anthraquinone-based sensitizers, and the like.

(C) The light absorbing agent (also referred to as a colorant, an organic pigment, or the like) is a component for adjusting the light absorption property of the photosensitive composition. The light absorber is typically a component that changes only the color of the photosensitive composition to adjust the transmittance of light. The light absorber may be an ultraviolet absorber that absorbs a part or all of light having a wavelength of ultraviolet light, an infrared absorber that absorbs a part or all of light having a wavelength of infrared light, or a visible light absorber (e.g., a black agent) that absorbs a part or all of light having a wavelength of visible light. The light absorbing agent may be used alone in 1 kind or in an appropriate combination of 2 or more kinds depending on, for example, the wavelength range of the light to be irradiated, as is conventionally known. Typical examples thereof include benzotriazole-based light absorbers, triazine-based light absorbers, benzophenone-based light absorbers, benzoate-based light absorbers, salicylate-based light absorbers, cyanoacrylate-based light absorbers, resorcinol-based light absorbers, hindered amine-based light absorbers, and the like.

In particular, the ultraviolet absorber has an effect of reducing the following phenomena: when ultraviolet exposure is performed, light penetrating from the opening of the photomask to the inside of the conductive film is scattered, and the light-shielding portion of the photomask is cured, so that the line width becomes wider than the opening width of the photomask.

As the ultraviolet absorber, those having a high absorption coefficient in the wavelength range of 250 to 520nm are preferable, and among them, organic dyes having a high absorption coefficient in the wavelength range of 350 to 450nm are preferable. Examples of the organic dye include azo dyes, benzophenone dyes, amino ketone dyes, xanthene dyes, quinoline dyes, amino ketone dyes, anthraquinone dyes, diphenylcyanoacrylate dyes, triazine dyes, and p-aminobenzoic acids. Of these, azo-based and benzophenone-based organic dyes are preferable.

Examples of the azo-based organic dye include sudan blue (sudan blue), sudan R, sudan II, sudan III, sudan IV, oil orange (oil orange) SS, oil violet (oil violet), and oil yellow (oil yellow) OB. Examples of the benzophenone-based organic dye include Uvinul (registered trademark) D-50(2,2 ', 4, 4' -tetrahydroxybenzophenone), Uvinul (registered trademark) MS40 (2-hydroxy-4-methoxybenzophenone 5-sulfonic acid), Uvinul (registered trademark) DS49 (sodium 2, 2-dihydroxy-4, 4 '-dimethoxybenzophenone-5, 5' -disulfonate), and the like, which are manufactured by BASF corporation.

(D) The polymerization inhibitor (also referred to as an inhibitor, a light stabilizer, a radical scavenger, an oxygen scavenger, or the like) is a component that interferes with the polymerization reaction of the photocurable component to improve at least one of the weatherability, heat resistance, and storage stability of the photosensitive composition. The polymerization inhibitor is a component for adjusting the photopolymerization (specifically, a polymerization reaction at a reduced rate) of the photosensitive composition. The polymerization inhibitor may be used alone in 1 kind or in an appropriate combination of 2 or more kinds from those known in the art. Typical examples thereof include hydroquinone, derivatives thereof, and phenol derivatives.

Subsequently, a plurality of photosensitive compositions were prepared by changing the mixing ratio of the prepared organic components stepwise with a predetermined conductive powder. Subsequently, in the same manner as in the calculation of the 1 st correlation formula, the prepared photosensitive compositions were applied to the substrates, and photocured and etched. Thereby, a fine wire-shaped wiring is formed. Next, the wiring on the substrate was observed with a laser microscope, and the line width of the wiring was measured from the obtained observation image. At this time, the line width is measured for a plurality of visual fields, and the arithmetic average value thereof is taken as the actual line width (actual line width). Then, for example, data is plotted on a graph in which the horizontal axis X represents the compounding ratio of the organic component in the photosensitive composition and the vertical axis Y represents the actual line width "the compounding ratio X of the organic component-the actual line width Y". From this graph, a correlation expression between the blending ratio of the organic component and the actual line width was calculated. Thus, the 2 nd correlation formula is prepared.

In this step, next, the compounding ratio of the organic component in the photosensitive composition is determined by the correlation equation 2 so as to eliminate the prediction variation width confirmed in step S2. In other words, the compounding ratio of the organic component in the photosensitive composition is determined so as to induce a target line width. In one example, the mixing of the carrier used in the calculation of the 1 st correlation equation is used as a basis. Then, the compounding ratio is changed from the carrier based on the calculated at least one of the organic components of the correlation 2. This makes it possible to eliminate the prediction error width confirmed in step S2. The organic component whose blending ratio is not changed may be the same as that of the base carrier. The mixing ratio may be changed to 1 type of organic component, and for example, when the predicted variation width is large, the total predicted variation width may be eliminated by changing the mixing ratio of 2 or more types of organic components little by little.

For example, when the predicted variation width is to be eliminated by using the polymerization initiator system, first, a correlation equation of the compounding ratio of the polymerization initiator system and the actual line width is prepared as the 2 nd correlation equation. For example, two correlation equations, i.e., a correlation equation between a compounding ratio of a photopolymerization initiator and an actual line width and a correlation equation between a compounding ratio of a sensitizer and an actual line width, are prepared. In the correlation equation, it is assumed that the compounding ratio of the polymerization initiator system has a positive correlation with the actual line width. In this case, if the expected line width is larger than the target line width, the compounding ratio of the polymerization initiator system is reduced based on the correlation formula so as to eliminate the predicted variation width by the compounding of the carrier as a base. On the other hand, if the expected line width is smaller than the target line width, the compounding ratio of the polymerization initiator system is increased so as to eliminate the predicted variation width by compounding the base carrier based on the correlation formula.

In addition, for example, when the predicted variation width is to be eliminated by using a polymerization inhibitor, first, a correlation between the ratio of the polymerization inhibitor to be blended and the actual line width is prepared as the 2 nd correlation. In the correlation, it is assumed that the compounding ratio of the polymerization inhibitor has a negative correlation with the actual line width. In this case, if the expected line width is larger than the target line width, the polymerization inhibitor compounding ratio is increased so as to eliminate the predicted variation width by compounding the base carrier based on the correlation formula. If the predicted line width is smaller than the target line width, the polymerization inhibitor compounding ratio is reduced based on the correlation formula so as to eliminate the predicted variation width by compounding the base carrier. As described above, the compounding ratio of the organic component in the photosensitive composition was determined.

The organic component for adjusting the blending ratio in this step is not limited to the components (a) to (D) described above. For example, the compounding ratio of at least one of the photocurable resin and the photocurable compound described later may be adjusted as long as other properties (for example, the adhesiveness of the conductive film to the substrate, etc.) are not significantly reduced. Further, for example, the blending ratio of other additive components described later can be adjusted.

< (step S4) Process for producing photosensitive composition

In this step, a photosensitive composition was prepared from the conductive powder of which the average particle diameter was actually measured in step S1. For example, first, an organic binder, a photocurable compound, a photopolymerization initiator, a sensitizer, a light absorber, a polymerization inhibitor, and other additive components used as needed are mixed in an organic dispersion medium to prepare a liquid vehicle. At this time, the respective components are added so that the photosensitive composition becomes the blending ratio determined in step S3. Next, the conductive powder and the carrier are mixed at a predetermined mixing ratio. Thus, a photosensitive composition was prepared. In the present embodiment, a photosensitive composition (paste-like photosensitive composition) containing an organic dispersion medium and prepared in a paste form (including a paste form and an ink form) can be obtained.

The organic binder (polymer component) is a component for improving the adhesion between the substrate and the uncured conductive film. The organic binder may have photosensitivity (which refers to a property of causing a chemical change or a structural change by light, for example, photocurability) or may not have photosensitivity. The organic binder comprises: a photopolymerizable oligomer (prepolymer) having a weight average molecular weight of 2000 or more and less than 5000, and a photopolymerizable polymer having a weight average molecular weight of 5000 or more. The organic binder may be used alone in 1 kind or in an appropriate combination of 2 or more kinds depending on the kind of the base material, the photopolymerizable compound, the photopolymerization initiator, and the like, for example, from those known in the art. As the organic binder, one that can be easily removed with a developer in the developing step is preferable. For example, when an alkaline developer is used in the developing step, the developer preferably has a hydroxyl group (-OH), a carboxyl group (-C (═ O) OH), an ester bond (-C (═ O) O-), and a sulfo group (-SO)₃H) And the like, which show an acidic moiety. This makes it difficult for residue to remain in unexposed portions, and can stably secure a space between thin lines, for example.

Examples of suitable organic binders include cellulose polymers such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and hydroxymethyl cellulose, acrylic resins, phenol resins, alkyd resins, polyvinyl alcohol, and polyvinyl butyral. Among them, hydrophilic organic binders, such as cellulose polymers and acrylic resins, are preferred from the viewpoint of easy removal in the developing step.

In addition, as the organic binder, a photocurable resin can be used. The photocurable resin is a photocurable component that is polymerized and cured by an active material generated from a photopolymerization initiator. The photocurable resin typically has at least one of 1 or more unsaturated bonds and a cyclic structure. The photocurable resin may be used alone in 1 kind or in an appropriate combination of 2 or more kinds from those conventionally known. Typical examples thereof include resins having an ethylenic double bond such as a (meth) acryloyl group, a vinyl group, and an allyl group, for example, acrylic resins and epoxy resins. In the present specification, "(meth) acryloyl group" is a term including "methacryloyl group" and "acryloyl group".

Specific examples of the acrylic resin include: a homopolymer of an alkyl (meth) acrylate such as polymethyl (meth) acrylate, polyethyl (meth) acrylate, polybutyl (meth) acrylate, or a copolymer containing an alkyl (meth) acrylate as a main monomer (a monomer occupying the maximum mass ratio) and a sub-monomer copolymerizable with the main monomer.

The photocurable compound (monomer component) is a photocurable component that is polymerized and cured by an active material generated from a photopolymerization initiator. The polymerization reaction may be, for example, addition polymerization or ring-opening polymerization. The photocurable compound may be radical polymerizable or cation polymerizable. The photocurable compound is a monomer having a weight average molecular weight of less than 2000. The photocurable compound may be used alone in 1 kind or in an appropriate combination of 2 or more kinds from those conventionally known. As a typical example, a (meth) acrylate monomer having a (meth) acryloyl group may be mentioned. The (meth) acrylate ester monomer comprises: monofunctional (meth) acrylates having 1 functional group per 1 molecule, polyfunctional (meth) acrylates having 2 or more functional groups per 1 molecule, and modifications thereof. Specific examples of the (meth) acrylate monomer include polyfunctional (meth) acrylates, urethane-modified (meth) acrylates having a urethane bond, epoxy-modified (meth) acrylates, silicone-modified (meth) acrylates, and the like. In the present specification, "(meth) acrylate" is a term including "methacrylate" and "acrylate".

The organic dispersion medium is a component that imparts appropriate viscosity and fluidity to the photosensitive composition to improve the handling properties of the photosensitive composition and the workability in forming a conductive film. The organic dispersion medium may be used alone in 1 kind or in an appropriate combination of 2 or more kinds from those conventionally known. Typical examples thereof include organic solvents such as alcohol solvents, glycol solvents, ether solvents, ester solvents, hydrocarbon solvents, and mineral essential oils. Among them, from the viewpoint of improving the storage stability of the photosensitive composition and the workability in forming the conductive film, an organic solvent having a boiling point of 150 ℃ or higher is preferable, and an organic solvent having a boiling point of 170 ℃ or higher is more preferable. In addition, as another suitable example, from the viewpoint of suppressing the drying temperature after printing the conductive film to a low level, an organic solvent having a boiling point of 250 ℃ or less is preferable, and an organic solvent having a boiling point of 220 ℃ or less is more preferable.

The other additive components may be used alone in 1 kind or in an appropriate combination of 2 or more kinds from those conventionally known. Examples thereof include antioxidants, plasticizers, surfactants, leveling agents, thickeners, wetting agents, dispersants, antifoaming agents, antistatic agents, anti-gelling agents, preservatives, fillers (organic fillers or inorganic fillers), glass powders, and ceramic powders (Al)₂O₃、ZrO₂、SiO₂Etc.), organic metal compounds (metal resinates), etc.

In the present embodiment, the mixing ratio of the conductive powder in the photosensitive composition is predetermined. The mixing ratio of the conductive powder is not particularly limited, and may be about 50 mass% or more, typically 60 to 95 mass%, for example 70 to 90 mass%. When the above range is satisfied, a conductive layer having high density and high conductivity can be formed. In addition, the workability of the photosensitive composition and the workability in forming a conductive film can be improved.

The ratio of the polymerization initiator in the entire photosensitive composition is not particularly limited, and may be about 5% by mass or less, typically 0.01 to 1% by mass, for example 0.02 to 0.5% by mass, 0.05 to 0.2% by mass. The ratio of the light absorbing agent may be set to substantially 0.5% by mass or less, typically 0.1% by mass or less, for example, 0.01% by mass or less, and further 0.001% by mass or less. The ratio of the polymerization inhibitor may be set to approximately 0.5% by mass or less, typically 0.1% by mass or less, for example, 0.001% by mass or less. The ratio of the photocurable resin to the entire photosensitive composition may be 5% by mass or less, typically 0.01 to 1% by mass, for example 0.02 to 0.5% by mass, 0.03 to 0.2% by mass. The ratio of the photocurable compound in the entire photosensitive composition may be 5% by mass or less, typically 0.01 to 1% by mass, for example 0.02 to 0.5% by mass, 0.03 to 0.2% by mass. The compounding ratio of the photocurable resin to the photocurable compound may be set to approximately 1: 10-10: 1. for example, 1: 3-3: 1. and further 1: 2-2: 1. the organic dispersion medium may be used in an amount of about 1 to 50 mass%, typically 3 to 30 mass%, for example 5 to 20 mass%. The ratio of the other additive components may be about 5% by mass or less, for example, 3% by mass or less.

Use of photosensitive composition

According to the photosensitive composition disclosed herein, a conductive layer having an L/S ratio of 30 μm/30 μm or less and an L/S ratio of 20 μm/20 μm or less can be stably formed. Therefore, the photosensitive composition disclosed herein can be suitably used for forming a conductive layer in various electronic components such as an inductor component, a capacitor component, and a multilayer circuit board. The electronic component may be mounted in various forms such as a surface mount type and a through-hole mount type. The electronic component may be a laminate type, a coil type, or a film type. Typical examples of the inductor component include a high-frequency filter, a common mode filter (common mode filter), an inductor (coil) for a high-frequency circuit, an inductor (coil) for a normal circuit, a high-frequency filter, a choke coil (choke coil), and a transformer (transformer).

In addition, the photosensitive composition in which the conductive powder contains the metal-ceramic core-shell particles can be suitably used for formation of a conductive layer of a ceramic electronic component. In the present specification, the term "ceramic electronic component" includes all electronic components having an amorphous ceramic substrate (glass ceramic substrate) or a crystalline (i.e., non-glass) ceramic substrate. Typical examples thereof include a High-frequency filter having a ceramic base material, a ceramic inductor (coil), a ceramic capacitor, a Low-Temperature-fired laminated ceramic base material (LTCC base material), and a High-Temperature-fired laminated ceramic base material (HTCC base material).

Fig. 3 is a cross-sectional view schematically showing the structure of the stacked-chip inductor 10. The dimensional relationships (length, width, thickness, etc.) in fig. 3 do not necessarily reflect actual dimensional relationships. In the drawing, reference numeral X, Y denotes a left-right direction and an up-down direction, respectively. Wherein it is merely a direction for ease of description.

The laminated chip inductor 10 includes: the liquid crystal display device includes a main body 11, and external electrodes 20 provided on both side surface portions of the main body 11 in a left-right direction X. The shape of the laminated chip inductor 10 is, for example, 1608 (1.6mm × 0.8mm), 2520 (2.5mm × 2.0mm), or the like. The main body 11 has a structure in which ceramic layers (dielectric layers) 12 and internal electrode layers 14 are integrated. The ceramic layer 12 is made of the above-described ceramic material as a covering portion that can constitute conductive powder, for example. The internal electrode layers 14 are disposed between the ceramic layers 12 in the vertical direction Y. The internal electrode layer 14 is formed using the photosensitive composition. The internal electrode layers 14 adjacent to each other in the vertical direction Y with the ceramic layers 12 interposed therebetween are electrically connected to each other through the through holes 16 provided in the ceramic layers 12. Thereby, the internal electrode layer 14 is formed in a three-dimensional spiral shape (spiral shape). Both ends of the internal electrode layer 14 are connected to external electrodes 20, respectively.

The stacked-chip inductor 10 can be manufactured, for example, by the following steps. That is, first, a paste containing a ceramic material, a binder resin, and an organic solvent as raw materials is prepared and supplied onto a carrier sheet to form a ceramic green sheet. Next, the ceramic green sheet is rolled and cut into a desired size to obtain a plurality of green sheets for forming a ceramic layer. Next, via holes are formed at predetermined positions of the ceramic layer forming green sheets by a punch or the like as appropriate. Next, a conductive film having a predetermined coil pattern is formed at a predetermined position of the plurality of ceramic layer-forming green sheets using the photosensitive composition. As an example, the conductive film in an unfired state can be formed by a manufacturing method including the steps of: a step (step A) of applying a photosensitive composition to a green sheet for forming a ceramic layer and drying the same to form a conductive film comprising a dried body of the photosensitive composition; (step B) a step of covering the conductive film with a photomask having a predetermined opening pattern, and exposing the conductive film through the photomask to partially photocure the conductive film: (step C) a step of removing uncured portions by etching the photo-cured conductive film.

When the photosensitive composition is used to form a conductive film, a conventionally known method can be suitably used. For example, in the step (a), the photosensitive composition can be applied by various printing methods such as screen printing, a bar coater, and the like. The drying of the photosensitive composition can be typically carried out at 50 to 100 ℃. In the step (B), an exposure apparatus that emits radiation such as visible light, ultraviolet light, X-rays, electron beams, α -rays, β -rays, and γ -rays may be used for the exposure. For example, an exposure machine that emits light in a wavelength range of 10 to 400nm, for example, an ultraviolet irradiation lamp such as a high-pressure mercury lamp, a metal halide lamp, or a xenon lamp, may be used. In the step (step C), an aqueous solution containing an alkali component such as sodium hydroxide or sodium carbonate can be used for etching.

Next, a plurality of ceramic layer-forming green sheets for forming an unfired conductive film are stacked and pressure-bonded. In this way, a laminate of unfired ceramic green sheets was produced. Next, the laminate of ceramic green sheets is fired at, for example, 600 to 1000 ℃. Thereby, the ceramic green sheet is integrally sintered to form the body portion 11, and the body portion 11 includes: ceramic layers 12, and internal electrode layers 14 of a baked body containing a photosensitive composition. Then, an appropriate external electrode forming paste is applied to both ends of the main body 11 and fired to form the external electrodes 20. In this manner, the stacked-chip inductor 10 can be manufactured.

Compounding ratio determining apparatus

Fig. 4 is a functional block diagram of the compounding ratio determination apparatus 30. The compounding ratio determination device 30 disclosed herein includes: an input unit 31, a storage unit 32, a 1 st calculation unit 33, a 2 nd calculation unit 34, and a display unit 35. The respective parts of the compounding ratio determining apparatus 30 are configured to be communicable with each other. Each part of the mixing ratio determining apparatus 30 may be constituted by software or hardware. The various parts of the compounding ratio determining apparatus 30 may be performed by a processor or may be incorporated in an electric circuit.

The input unit 31 is configured to: the operation input of a user (for example, an operator for preparing the photosensitive composition) can be received, and the type and average particle diameter (measured value) of the conductive powder to be used, and the target line width can be input. When a plurality of kinds of conductive powders are used in combination, the mixing ratio of the conductive powders can be further input. The type of the conductive powder is, for example, information represented by a place of purchase, a product name (product name), a product number, and the like. The type of the conductive powder may be, for example, the structure (whether or not it is a core-shell structure) of the conductive powder, the average particle diameter (nominal value), the average aspect ratio, and the luminance L^*And the like. The input unit 31 includes, for example, a keyboard having cursor keys, numeric input keys, and the like, a pointing device such as a mouse, and an input device such as a button (not shown). The input unit 31 may be configured to select the type of conductive powder from a pull-down menu displayed on the display unit 35, for example. The input unit 31 may be configured to acquire the above-described information from an external device such as a host computer through a network connected by wire or wirelessly, for example. In the present embodiment, the "target line width" is an example of a predetermined target level.

The storage unit 32 stores the 1 st correlation equation and the 2 nd correlation equation. The 1 st correlation formula and the 2 nd correlation formula are stored in the storage unit 32 in advance according to the type of the conductive powder (for example, according to the product name). Therefore, typically, the 1 st correlation expression and the 2 nd correlation expression stored in the storage unit 32 are plural. The 1 st correlation may be represented by a linear function. The 1 st correlation formula is not particularly limited, and is, for example, a correlation formula between the average particle diameter (measured value) of the conductive powder and the actual line width. The 2 nd correlation has a prescribed slope (rate of change). The 2 nd correlation may be expressed as a linear function. The correlation formula 2 is not particularly limited, and is, for example, a correlation formula of a compounding ratio of the organic component (for example, a polymerization initiator system) and an actual line width. The storage unit 32 may further store the composition of the carrier as a base, that is, the type and the blending ratio of each organic component contained in the carrier.

If the user performs an input operation of the type and average particle diameter (measured value) of the conductive powder to be used from the input unit 31, the 1 st calculating unit 33 refers to the 1 st correlation formula of the conductive powder of the same type as the input conductive powder from the 1 st correlation formula stored in the storage unit 32. Then, the predicted deviation width from the target line width is calculated from the average particle diameter (actually measured value) input from the input unit 31. For example, in the case where the 1 st correlation formula is expressed by a correlation formula between the average particle diameter (actually measured value) of the conductive powder and the actual line width, first, the average particle diameter (actually measured value) input in the input unit 31 is interpolated into the corresponding 1 st correlation formula, and the expected line width is calculated. Then, the difference between the expected line width and the target line width input from the input unit 31 by the user is calculated as the predicted deviation width. In the present embodiment, the "predicted deviation width" is an example of the predicted deviation value.

If the 1 st calculating unit 33 calculates the predicted deviation width, the 2 nd calculating unit 34 refers to the 2 nd correlation formula of the same kind of conductive powder as the input conductive powder from the 2 nd correlation formula stored in the storage unit 32. Then, the blending ratio of the organic component is calculated based on the predicted deviation width calculated by the 1 st calculating unit 33. For example, when the 2 nd correlation expression is expressed by a correlation expression between the compounding ratio of the polymerization initiator system and the actual line width, the predicted deviation width is divided by the slope of the 2 nd correlation expression, and the compounding ratio of the polymerization initiator system for eliminating the predicted deviation width is calculated. Then, the final compounding ratio is set by increasing or decreasing the compounding ratio for eliminating the predicted variation width from the compounding ratio of the photopolymerization initiators contained in the carrier.

The compounding ratio determination device 30 is, for example, a computer, and includes: a Central Processing Unit (CPU) for executing commands of a control program, a rom (read only memory) in which a program executed by the CPU is stored, a ram (random access memory) used as a work area for developing the program, and a storage device such as a memory in which the program and various data are stored. The compounding ratio determining device 30 may be a computer program configured to cause a CPU of a computer to operate as each section of the compounding ratio determining device 30. The computer program may be a recording medium that is written in the operation of the compounding ratio determining apparatus 30 and can be read by a computer.

As the recording medium, for example, a semiconductor recording medium (e.g., ROM, a nonvolatile memory card), an optical recording medium (e.g., a Digital Video Disc (DVD), a magneto-optical disc (MO), a Mini Disc (MD), an optical disc (CD), a blu-ray disc (BD)), a magnetic recording medium (e.g., a magnetic tape, a floppy disk), and the like can be exemplified. The computer program may be transmitted to the server computer via the recording medium or a network such as the internet or an intranet. In this case, the server computer is also one form of the compounding ratio determination apparatus 30.

The following description will be made of several embodiments of the present invention, but the present invention is not intended to be limited to the embodiments shown.

< example 1: case where 1 kind of conductive powder is used alone >

Hereinafter, a case of producing a photosensitive composition by using 1 kind of conductive powder alone will be described. As a preliminary preparation, first, the 1 st correlation formula and the 2 nd correlation formula corresponding to the conductive powder to be used are prepared. Specifically, the 1 st correlation equation shown in fig. 5 and the 2 nd correlation equation shown in fig. 6 are prepared. Fig. 6 is a 2 nd correlation formula for adjusting the compounding ratio of photopolymerization initiators.

The 1 st correlation shown in fig. 5 is prepared as follows. That is, first, a plurality of (here, 15) kinds of commercially available silver powders having an average particle diameter (nominal value) of approximately 3 μm were prepared as conductive powders. Next, the average particle diameters of 15 kinds of silver powders were measured by wet measurement in a dispersion solvent using a particle size distribution measuring apparatus (model "MT-3000 II" manufactured by Microtrac BEL Co., Ltd., measurement range: 0.02 to 2800 μm) by a laser diffraction/scattering method. As the dispersion solvent, an alcohol solvent (specifically, ethanol) is used from the viewpoint of suppressing aggregation of the silver powder and dispersing each particle in the dispersion solvent. Then, a volume-based particle size distribution was obtained. It should be noted that the particle size distribution is typically unimodal with a mode diameter (mode particle diameter) of only 1. The average particle diameters (measured values) of 15 kinds of silver powders were read from the particle size distribution, respectively.

Next, an organic binder, a photocurable compound, a photopolymerization initiator, a sensitizer, an ultraviolet absorber as a light absorber, and a polymerization inhibitor were dissolved in an organic dispersion medium in the composition shown in table 1 to prepare a carrier. Next, the 15 kinds of silver powders prepared above were mixed with a carrier in a ratio of 77: 23 to prepare photosensitive compositions, respectively.

[ Table 1]

TABLE 1 composition of the vectors

Subsequently, the photosensitive compositions prepared above were coated on commercially available ceramic green sheets by screen printing. Then, the sheet was dried at 60 ℃ for 15 minutes to form a conductive film (a whole film) on the green sheet (a conductive film forming step). Next, a photomask is covered with the conductive film. As the photomask, a photomask having an L/S of 25 μm/25 μm was used. The photomask was covered on the conductive film by an ultraviolet exposure machine at 2500mJ/cm²The conductive film is partially cured by irradiating light with the intensity of (1) (exposure step). After exposure, 0.4 mass% of Na was blown to the ceramic green sheet₂CO₃The uncured conductive film is partially etched and removed with an aqueous solution, and then cleaned with pure water and dried at room temperature (developing step). In this manner, a wiring pattern is formed on the ceramic green sheet.

Next, the wiring pattern was observed with a laser microscope, and the line width of the wiring was measured from the obtained observation image. The line width is measured for a plurality of visual fields, and the arithmetic average value thereof is defined as the actual line width (actual line width). As shown in fig. 5, the correlation between the average particle diameter (measured value) of 15 kinds of silver powder and the actual line width was shown in a graph, and a correlation formula (Y: 5.593X +11.192) was calculated. In the 1 st correlation shown in FIG. 5, the average particle diameter (measured value) of the silver powder is proportional to the actual line width using the photosensitive composition containing the silver powder (correlation coefficient: 0.92). The 1 st correlation shown in fig. 5 is expressed by a linear function. In fig. 5, the average particle diameter (measured value) has a positive correlation with the actual line width. That is, as the average particle diameter (measured value) of the silver powder becomes larger, the line width becomes linearly thicker.

The 2 nd correlation equation of fig. 6 is prepared as follows. That is, first, a predetermined silver powder is prepared as a conductive powder. Further, an organic binder, a photocurable compound, a photopolymerization initiator, a sensitizer, an ultraviolet absorber, a polymerization inhibitor, and an organic dispersion medium were mixed at the compounding ratio shown in table 1 to prepare a base carrier. Next, the silver powder was mixed with a carrier in a ratio of 77: 23 to prepare a base photosensitive composition.

Next, from the photosensitive composition to be the base, the compounding ratio of the photopolymerization initiators (photopolymerization initiator and sensitizer) was changed as shown in table 2. In this case, the amount of the organic dispersion medium is increased or decreased to adjust the portion in which the blending ratio of the photopolymerization initiators is increased or decreased. For example, when the blending ratio of the photopolymerization initiators is decreased from 0.550 to 0.515, the amount of the organic dispersion medium is increased in accordance with the above portion (0.035). A plurality of (here, 5 patterns) of such photosensitive compositions were prepared. When the blending ratio of the photopolymerization initiators is changed, the ratio of the photopolymerization initiator to the sensitizer is made constant. Then, using the plural kinds of photosensitive compositions prepared above, a wiring pattern was formed in the same manner as in the calculation of the above-mentioned correlation formula 1, and an actual line width was obtained. Then, the correlation between the compounding ratio of the photopolymerization initiator in the photosensitive composition of 5 patterns and the actual line width was shown in a graph, and a correlation formula (Y: 74.927X +19.762) was calculated.

[ Table 2]

TABLE 2 compounding ratio of photopolymerization initiators

Compounding ratio in Carrier (% by mass)	0.621	0.585	0.550	0.515	0.479
						Compounding ratio (mass%) in photosensitive composition	0.143	0.135	0.127	0.118	0.110
Actual line width (mum)	30.5	29.7	29.5	28.4	28.1

In the correlation 2 in FIG. 6, the compounding ratio of the polymerization initiator system in the photosensitive composition is proportional to the actual line width (correlation coefficient: 0.96). The 2 nd correlation equation of fig. 6 is expressed by a linear function. In fig. 6, the compounding ratio of the polymerization initiator system has a positive correlation with the actual line width. That is, it is found that the line width linearly becomes thicker as the compounding ratio of the polymerization initiator system becomes larger.

In example 1, after aligning the 1 st correlation formula and the 2 nd correlation formula as described above, silver powder (average particle diameter (nominal value): 3 μm) used for the photosensitive composition was prepared as step S1. Next, the average particle diameter of the silver powder was actually measured under the same measurement and analysis conditions using the same particle size distribution measuring apparatus as used in the calculation of the correlation 1. Then, the average particle diameter (measured value) of the silver powder was read from the particle size distribution of the volume basis. Here, the measured value was 3.17. mu.m.

Next, as step S2, the measured value obtained in step S1 is compared with the 1 st correlation formula in fig. 5. Then, the predicted deviation width from the predetermined target line width is confirmed. Here, if the measured value is 3.17 μm and is interpolated into the 1 st correlation equation (Y: 5.593X +11.192) in fig. 5, the expected line width is calculated to be 28.92 μm. Therefore, when the target line width is 27.3 μm, the predicted variation width is calculated to be +1.62 μm from (the expected line width of 28.92 μm) - (the target line width of 27.3 μm). That is, it is found that if a photosensitive composition is prepared directly according to the composition of the base support, the line width thicker than the target line width by 1.62 μm is highly likely to occur.

Therefore, next, as step S3, the blending ratio of the organic component is changed so as to eliminate the predicted variation width and approach the target line width. Here, the compounding ratio of the polymerization initiator system was adjusted based on the 2 nd correlation formula (Y: 74.927X +19.762) of fig. 6. That is, the value obtained by dividing the predicted deviation width +1.62 μm by the slope 74.927 of the 2 nd correlation equation (1.62/74.927) +0.022 is the amount of the polymerization initiator system in the portion where the predicted deviation width +1.62 μm is adjusted. Therefore, in order to eliminate the prediction variation width, the ratio of the polymerization initiator system was reduced by 0.022 mass% from the base photosensitive composition. Table 3 shows an example of the compounding ratio of the polymerization initiator system determined in consideration of the predicted variation width.

[ Table 3]

TABLE 3 compounding ratio of photopolymerization initiators

The opposite plus sign (+) indicates a width relative to the target line.

Next, as step S4, carriers with the mixing ratio of the polymerization initiator system changed were prepared as shown in table 3. The organic components not shown in table 3, for example, the organic binder, the photocurable compound, the ultraviolet absorber, and the polymerization inhibitor are the same as those added to the base photosensitive composition. Next, the silver powder of which the average particle diameter was actually measured in step S1 was mixed with a carrier to prepare a photosensitive composition. Then, a wiring pattern is formed, and an actual line width is measured. As a result, the actual line width was 27.4. mu.m. That is, the line width is significantly closer to the target line width (27.3 μm) than the line width (29.0 μm) expected in step S2.

Further, with respect to the plurality of kinds of conductive powders, the technique disclosed herein was applied in the same manner as described above to prepare a photosensitive composition, and the actual line width was measured. That is, an actual measurement value of the average particle diameter of the silver powder is obtained in step S1, a prediction variation width is confirmed in step S2, a compounding ratio of the polymerization initiator system is determined in step S3, the compounding ratio of the carrier is adjusted, a photosensitive composition is prepared, and an actual line width is measured. The results are shown in Table 4. The right end of table 4 shows the results of example 1. In addition, as a reference example, the actual line width (μm) when the base carrier is used as it is (that is, the compounding ratio of the polymerization initiator system is not adjusted so as to be constant) is described in the lowest stage, without applying the technique disclosed herein.

[ Table 4]

TABLE 4 compounding ratio of polymerization initiators

The corresponding sign (+) indicates a large width with respect to the target line, and the corresponding sign (-) indicates a small width with respect to the target line.

The opposite side 2, plus (+) indicates a decrease in the compounding ratio and minus (-) indicates an increase in the compounding ratio.

Fig. 7 is a graph summarizing the results of table 4 and comparing actual line widths in the presence or absence of application of the technology disclosed herein. As is clear from fig. 7 and table 4, by applying the technique disclosed herein, variations between manufacturing lots of the conductive powder are relatively buffered and fluctuations in line width can be suppressed, as compared with the case (reference example) in which the technique disclosed herein is not applied. Here, the variation of the line width can be suppressed to. + -.1 μm or less, and further to. + -.0.5 μm or less. In other words, a fine line-shaped wiring can be stably formed in the vicinity of a target line width. The above results embody the significance of the techniques disclosed herein.

< example 2: case where 2 kinds of conductive powders were mixed and used >

Hereinafter, a case of producing a photosensitive composition using a mixed powder in which 2 kinds of conductive powders are mixed will be described. As a preliminary preparation, first, 2 1 st correlation expressions corresponding to the 2 kinds of conductive powders used are prepared. Specifically, the 1 st correlation formula shown by a solid line in fig. 8 and 9 is prepared. In addition, the 2 nd correlation formula is also prepared. As for the 2 nd correlation formula, the same one as the correlation formula shown in fig. 6 is prepared.

The 1 st correlation equation shown by a solid line in fig. 8 is prepared as follows. That is, first, plural kinds (here, 7 kinds) of the 1 st silver powder having an average particle diameter (nominal value) of approximately 2.9 μm are prepared as the 1 st conductive powder. Then, in the same manner as when calculating the 1 st correlation formula of fig. 5 of example 1, the average particle diameter (measured value) of each of the 7 1 st silver powders was actually measured. As the 2 nd conductive powder, a 2 nd silver powder having an average particle diameter (measured value) of 2.56 μm was prepared. Next, the 1 st silver powder and the 2 nd silver powder were mixed at a predetermined ratio (here, 40: 60) by mass to adjust the mixed powder. The mixed powder was mixed with a carrier shown in table 1 at 77: 23 to prepare a photosensitive composition. Then, a wiring pattern was formed using the photosensitive composition in the same manner as in example 1, and a correlation formula (Y: 1.89X +24.85) between the average particle diameter (actually measured value) and the actual line width was calculated.

The 1 st correlation equation shown by a solid line in fig. 9 is prepared as follows. That is, first, a plurality of (here, 5) kinds of 2 nd silver powders having an average particle diameter (nominal value) of approximately 2.4 μm are prepared as the 2 nd conductive powder. Then, the average particle diameter (measured value) of each of the 5 kinds of 2 nd silver powders was actually measured in the same manner as when the 1 st correlation formula in fig. 5 of example 1 was calculated. Further, as the 1 st conductive powder, a 1 st silver powder having an average particle diameter (measured value) of 3.06 μm was prepared. Next, the 1 st silver powder and the 2 nd silver powder were mixed in a ratio of 40: 60, to thereby adjust the mixed powder. Then, in the same manner as in the case of calculating the 1 st correlation equation in fig. 8, a correlation equation (Y is 2.12X +24.72) between the average particle diameter (actually measured value) and the actual line width is calculated.

In the case of the 1 st correlation formula shown by the solid line in fig. 8 and 9, the average particle diameter (actually measured value) of the silver powder after the change is proportional to the actual line width (correlation coefficient: 0.92 or more), as in the case of the 1 st correlation formula shown in fig. 5 of example 1. The 1 st correlation equation shown by a solid line in fig. 8 and 9 is shown by a linear function. In fig. 8 and 9, the average particle diameter (measured value) has a positive correlation with the actual line width.

In example 2, after aligning 2 1 st correlation equations as described above, 2 kinds of conductive powders, i.e., the 1 st silver powder (average particle diameter (nominal value): 2.9 μm) and the 2 nd silver powder (average particle diameter (nominal value): 2.4 μm) used in the photosensitive composition were prepared as step S1. Next, in the same manner as in the case of calculating the 1 st correlation formula of fig. 8 and 9, the average particle diameters of the 1 st silver powder and the 2 nd silver powder were measured. Next, as step S2, the measured value of the 1 st silver powder obtained in step S1 is compared with the 1 st correlation formula (Y ═ 1.89X +24.85) in fig. 8. The measured value of the 2 nd silver powder was compared with the 1 st correlation formula (Y ═ 2.12X +24.72) in fig. 9. Next, predicted deviation widths α 1 and α 2 with respect to the target line width (here, 30.0 μm) were calculated for the 2 silver powders. That is, if the measured values of the 1 st silver powder and the 2 nd silver powder are x1 and x2, and the predicted line widths are y1 and y2, the predicted deviation widths α 1 and α 2 are obtained by the following equations.

α1＝y1-30.0＝1.89×x1+24.85-30.0

α2＝y2-30.0＝2.12×x2+24.72-30.0

Then, the predicted deviation width β (μm) when 2 kinds of conductive powders are mixed and used is obtained from the following equation using the predicted deviation widths α 1 and α 2.

β＝α1+α2

Next, as step S3, the compounding ratio of the polymerization initiator system contained in the carrier was adjusted as shown in tables 5 and 6 in the same manner as in example 1. Next, as step S4, a photosensitive composition was prepared in the same manner as in example 1. Then, a wiring pattern is formed, and an actual line width is measured.

[ Table 5]

TABLE 5 compounding ratio of photopolymerization initiators

In addition, the method is as follows: plus (+) denotes a thick line width and minus (-) denotes a thin line width.

[ Table 6]

TABLE 6 compounding ratio of photopolymerization initiators

As is clear from tables 5 and 6, by applying the technique disclosed herein, even when 2 kinds of conductive powders are mixed and used, the variation between the production lots of the conductive powders can be buffered and the fluctuation in the line width can be suppressed. Here, the variation of the line width can be suppressed to. + -.1 μm or less, and further to. + -.0.5 μm or less.

In the correlation formula 1 shown by a dotted line in fig. 8 and 9, the ratio of the 1 st silver powder to the 2 nd silver powder is 70: 30 in the mass ratio of 30. Even when the mixing ratio is changed in this way, the average particle diameter (measured value) of the silver powder after the change is proportional to the actual line width as a linear function (correlation coefficient: 0.95 or more) as in the case of the 1 st correlation expression shown by the solid line. The average particle diameter (measured value) has a positive correlation with the actual line width. It is thus assumed that: the technique disclosed herein can be applied to various mixed powders regardless of the mixing ratio.

The preferred embodiments of the present invention have been described above. However, the above embodiments are merely examples, and the present invention may be implemented in other various forms. The present invention can be implemented based on the contents disclosed in the present specification and the technical common knowledge in the field. The technology described in the claims includes various modifications and changes of the embodiments exemplified above. For example, some of the above embodiments may be combined with or replaced with other modifications. In addition, if the technical features are not necessarily described, they may be deleted as appropriate.

In the above embodiment, the target level factor is defined as "line width", but is not limited thereto. The target level factor is only required to be due to the light absorption and light curing of the conductive film, and may be, for example, the film thickness, electrode cross-sectional area, curing shrinkage, resistance value, and the like of the conductive film. That is, as is clear from fig. 1 (a) and (B), scattering of light changes according to the difference in particle size of the conductive powder, and as a result, the light absorption of the conductive film changes, and the photocuring degree changes. From this viewpoint, it is obvious to those skilled in the art that not only the line width described above but also the film thickness, cross-sectional area, curing shrinkage ratio, and the like can be changed similarly depending on the difference in particle diameter of the conductive powder. It is obvious to those skilled in the art that the resistance value can be changed similarly.

This is considered to be confirmed by, for example, the following references 1 to 3:

reference 1: yujiazhixianxiao, CMC Library of science and technology (Technical Library)206, plastic surface treatment technology and material, P.67, a correlation graph of light transmittance (%) and particle size (mum) of a coating film;

reference 2: polymer technology report, vol.5 (2011), p.20, fig. 15 (relationship between the reaction rate of hexanediol diacrylate and curing time when the intensity of the irradiated light is changed);

reference 3: the information technology association issued a formulation design, characteristic evaluation, and new application of UV curable resin, p.470, fig. 16 (change in film thickness during curing shrinkage of UV resist).

If the description of the above document is taken into consideration, it is inferred that: for example, in the range of 0.1 to 10 μm, the factor of the light absorption and light curing degree is monotonously increased or monotonously decreased with the change of the particle diameter of the conductive powder. That is, it is considered that the variation of the line width with the shift of the particle diameter is proportional to the shift or becomes a transition with high correlation with a constant function. From the above, it can be said that the fluctuation of the buffer line width is synonymous with the fluctuation of the factors related to the light absorbance and the light curing degree. That is, it is considered that in the technology disclosed herein, the "target level" may be a target line width, a target film thickness, a target cross-sectional area, a target curing shrinkage rate, and a target resistance value. The "predicted deviation value" may be a deviation width, a deviation thickness, a deviation cross-sectional area, a deviation curing shrinkage rate, or a deviation resistance value corresponding to the target level.

In the above embodiment, step S3 is performed after step S2, but the present invention is not limited thereto. For example, after step S2, it may include: and a determination step of comparing the predicted deviation width with a preset threshold value. If it is determined in the determination step that the prediction deviation width is smaller than the threshold value, step S3 may be omitted and step S4 may be performed.

In the above embodiment, the correlation between the average particle diameter (measured value) and the actual line width is shown as the 1 st correlation, but the present invention is not limited thereto. As a variable to be compared with the average particle diameter (measured value), for example, a predicted variation width obtained by subtracting a target line width from an actual line width can be used. That is, the 1 st correlation equation can be expressed as a correlation equation between the average particle diameter (actually measured value) and the prediction variation width. In this case, the actual measurement value obtained in step S1 may be interpolated into the correlation expression, and the prediction error width may be directly checked.

In the above embodiment, the correlation between the compounding ratio of the organic component in the photosensitive composition and the actual line width is shown as the correlation 2, but the present invention is not limited thereto. As a variable to be compared with the blending ratio of the organic component, for example, a predicted deviation width can be set as in the case of the 1 st correlation expression. The compounding ratio of the organic component may be expressed by, for example, a compounding ratio in the carrier, instead of the compounding ratio in the photosensitive composition.

In the above embodiment, the mixing ratio determining apparatus 30 includes: the input unit 31, the storage unit 32, the 1 st calculation unit 33, and the 2 nd calculation unit 34 are not limited thereto. The mixing ratio determining device 30 may further include at least 1 of the following components in addition to the above components: a 1 st setting unit that sets a 1 st correlation expression for a predetermined type of conductive powder and stores the set expression in the storage unit 32; a 2 nd setting unit that sets a 2 nd correlation expression for a predetermined type of conductive powder and stores the result in the storage unit 32; a notification unit configured to notify a user of an error when the 1 st correlation formula or the 2 nd correlation formula of the same type as the input conductive powder is not stored in the storage unit 32; and the like.

In examples 1 and 2, silver powder was used as the conductive powder, but the present invention is not limited thereto. The same mechanism as that of using a conductive powder having a large average particle diameter is applied to other metal species, that is, the mechanism in which irradiation light easily diffuses in the horizontal direction of the conductive film in the exposure step and the line width of the wiring easily becomes thick. The technique disclosed herein can be applied not only to silver powder, but also to powder containing the above-mentioned various metals, for example, copper, platinum, palladium, aluminum, nickel, and the like.

In examples 1 and 2, the average particle diameter (D50 particle diameter) of the conductive powder, specifically, the particle diameter corresponding to 50% of the cumulative value from the smaller particle diameter side in the volume-based particle size distribution was measured in step S1, but the present invention is not limited thereto. In step S1, a volume-based particle size distribution may be replaced with a number-based particle size distribution or the like. The particle size factor may be, for example, a D40 particle size (particle size corresponding to a cumulative value of 40% from the smaller particle size side in the particle size distribution), a D60 particle size (particle size corresponding to a cumulative value of 60% from the smaller particle size side in the particle size distribution), or the like, instead of the average particle size (D50 particle size). In this case, the 1 st correlation equation may be expressed by "particle size (measured value) X — actual line width Y of D40", "particle size (measured value) X — actual line width Y of D60", and the like. Further, for example, when the particle size distribution of the conductive powder is unimodal, the particle size factors may be particle sizes further deviated from the average particle size, for example, a D5 particle size (a particle size corresponding to a cumulative value of 5% from a smaller particle size side in the particle size distribution), a D90 particle size (a particle size corresponding to a cumulative value of 90% from a smaller particle size side in the particle size distribution), a D95 particle size (a particle size corresponding to a cumulative value of 95% from a smaller particle size side in the particle size distribution), and the like.

In examples 1 and 2, the 2 nd correlation expression of the polymerization initiator system was prepared and the compounding ratio of the photopolymerization initiators was adjusted to suppress the fluctuation of the line width in step S3, but the present invention is not limited thereto. The organic component for adjusting the compounding ratio may be, for example, any of a photopolymerization initiator and a sensitizer.

In examples 1 and 2, the 2 nd correlation formula of the polymerization initiator system was prepared in step S3, but instead of or in addition to this, for example, the 2 nd correlation formula of the light absorber (see fig. 10) was prepared, and the blending ratio of the light absorber was adjusted, whereby the fluctuation in line width could be suppressed. In the correlation 2 shown in fig. 10, the compounding ratio of the ultraviolet absorber in the photosensitive composition and the actual line width are represented by a logarithmic curve. Since the change in the logarithmic curve is rapid, for example, when the predicted deviation width is large, there is an advantage that the blending ratio can be changed only slightly. Further, for example, the polymerization inhibitor can be prepared in the correlation formula 2 (see fig. 11), and the line width fluctuation can be suppressed by adjusting the polymerization inhibitor compounding ratio. In the correlation 2 shown in FIG. 11, the compounding ratio of the photopolymerization initiator in the photosensitive composition is proportional to the actual line width (correlation coefficient: 0.99). The 2 nd correlation shown in fig. 11 is expressed by a linear function. The compounding ratio of the polymerization inhibitor has a negative correlation with the actual line width. That is, it is found that the line width linearly becomes smaller as the compounding ratio of the polymerization inhibitor system becomes larger. This type of correlation 2 can be suitably used in the technique disclosed herein, as in the correlation 2 shown in fig. 6 and 7.

Description of the reference numerals

10-stacked chip inductor

11 body part

12 ceramic layer

14 internal electrode layers

20 external electrode

30 compounding ratio determining device

31 input unit

32 storage part

33 the 1 st calculating unit

34 the 2 nd calculation unit

35 display part

Claims

1. A method for producing a photosensitive composition containing a conductive powder at a predetermined compounding ratio,

the manufacturing method comprises the following steps:

a step of measuring the particle diameter of the conductive powder to obtain an actual measurement value;

comparing the measured value with a previously prepared 1 st correlation formula, that is, a 1 st correlation formula of the particle diameter of the conductive powder and an arbitrary factor that fluctuates in association with a shift of the particle diameter and that fluctuates due to light absorption or light curing of the conductive film, and confirming a predicted deviation value of the factor from a predetermined target level;

and determining the blending ratio of the organic component so as to eliminate the predicted deviation value based on a previously prepared 2 nd correlation formula, that is, a factor in the 1 st correlation formula and a 2 nd correlation formula of an arbitrary organic component contained in the photosensitive composition and having a variation in the blending ratio related to a variation in the factor.

2. The method for producing a photosensitive composition according to claim 1, wherein,

the organic component is an organic component for adjusting at least one of light absorptivity and photopolymerization of the photosensitive composition.

3. The method for producing a photosensitive composition according to claim 1, wherein,

the organic component is at least one of a photopolymerization initiator, a light absorber, and a polymerization inhibitor.

4. The method for producing a photosensitive composition according to claim 1, wherein,

the organic component is a photopolymerization initiator.

5. The method for producing a photosensitive composition according to any one of claims 1 to 4,

the factor in the 1 st correlation formula is a line width, a film thickness, an electrode cross-sectional area, a curing shrinkage rate, or a resistance value of the conductive film.

6. The method for producing a photosensitive composition according to any one of claims 1 to 5, wherein,

the factor in the 1 st correlation is the line width.

7. The method for producing a photosensitive composition according to any one of claims 1 to 6, wherein,

the 2 nd correlation is expressed by a linear function.

8. The method for producing a photosensitive composition according to any one of claims 1 to 7, wherein,

the conductive powder contains silver-based particles.

9. The method for producing a photosensitive composition according to any one of claims 1 to 8, wherein,

the conductive powder includes core-shell particles including a metal material that becomes a core, and a ceramic material that covers at least a part of a surface of the core.

10. The method for producing a photosensitive composition according to any one of claims 1 to 9,

use of the photosensitive composition for forming an electrode.

11. A method for manufacturing an electronic component, comprising the steps of:

a photosensitive composition obtained by the production method according to any one of claims 1 to 10 is applied onto a substrate, photocured, etched, and then baked to form a conductive layer including a baked product of the photosensitive composition.

12. A mixing ratio determining device for determining a mixing ratio of an organic component to a photosensitive composition containing a conductive powder at a predetermined mixing ratio,

the compounding ratio determining apparatus includes:

an input unit for receiving user input and inputting the type of the conductive powder used and the measured value of the particle size;

a storage unit that stores a previously prepared 1 st correlation formula, that is, a 1 st correlation formula of the particle diameter of the conductive powder and an arbitrary factor that fluctuates in association with a shift in the particle diameter due to a fluctuation caused by light absorption or light curing of a conductive film, and a previously prepared 2 nd correlation formula, that is, a factor in the 1 st correlation formula and an arbitrary organic component that is contained in the photosensitive composition and in which a fluctuation in a compounding ratio is associated with a fluctuation in the factor;

a 1 st calculation unit that calculates a predicted deviation value of a factor in the 1 st correlation equation from a predetermined target level from the measured value input by the input unit based on the 1 st correlation equation; and the combination of (a) and (b),

and a 2 nd calculating unit that calculates a blending ratio of the organic component in the 2 nd correlation equation from which the prediction bias value is eliminated, based on the 2 nd correlation equation.

13. The compounding ratio determining apparatus according to claim 12,

14. A computer program configured to cause a computer to function as the compounding ratio determination apparatus according to claim 12 or 13.

15. An electronic component comprising a conductive layer containing a baked product of the photosensitive composition obtained by the production method according to any one of claims 1 to 10.

16. A paste-like photosensitive composition, wherein,

the photosensitive composition obtained by the production method according to any one of claims 1 to 10, comprising an organic dispersion medium.