JP2014009262A - Printing ink, printed wiring board, method of manufacturing printed wiring board, display device, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board which has a conductive layer having high adhesion to an inorganic material, and to provide a printing ink used for the same.SOLUTION: The printing ink containing zinc oxide particles is used. After the printing ink is applied on an inorganic substrate, a printing ink layer is heated in a gas containing formic acid and an organic compound having a nitrogen-containing heterocyclic structure to obtain the printed wiring board.

Description

  The present invention relates to a printing method ink, a printed wiring board, a method for manufacturing a printed wiring board, a display device, and a solar cell module.

  In recent years, the formation of a wiring pattern by a printing method has been regarded as promising because it is superior in low energy, low cost, high throughput, on-demand production, and the like. In this forming method, after a pattern is formed by a printing method using an ink paste containing a metal element, a wiring pattern is obtained by imparting metal conductivity to the printed ink paste pattern.

  Conventionally, in this method, a conductive paste in which metal particles such as flaky silver or copper are mixed with a thermoplastic resin, a thermosetting resin binder, an organic solvent, a curing agent, a catalyst, or the like has been used. This conductive paste is applied to an object by dispenser or screen printing and dried at room temperature, or heated to about 150 ° C. to cure the binder resin to form a conductive film. In the conductive film thus obtained, only a part of the internal metal particles are in physical contact to establish conduction, and the cured resin exhibits strength of the conductive layer and adhesion to the substrate. Yes.

However, in such a conductive paste, contact between the metal particles is hindered by the binder remaining between some of the metal particles. Therefore, although the volume resistivity which is a parameter | index of electroconductivity is based on film forming conditions, it is the range of 10 < ^-6 > (omega | ohm) * m-10 < ^-7 > (omega | ohm) * m, and the volume resistivity 16 * 10 < ^-9 > of metal silver or copper. The value is 10 to 100 times that of Ω · m, 17 × 10 ⁻⁹ Ω · m, and the value does not reach the metal film. Further, in the conventional silver paste, since the silver particles are in the form of flakes having a particle diameter of 1 μm to 100 μm, it is impossible in principle to print a wiring having a line width equal to or smaller than the particle diameter of the flaky silver particles. From these points, the conventional silver paste is not suitable for forming a fine wiring pattern.

  In order to overcome the disadvantages of these silver and copper pastes, a method for forming a wiring pattern using metal nanoparticles has been studied, and a method using gold, silver or copper nanoparticles has been reported. As the printing method ink for forming such a wiring pattern (conductor layer), for example, an ink containing at least metal nanoparticles and having a carbon atom content of 0.4 mass% or less in all solid sentences is disclosed. (For example, refer to Patent Document 1). This ink for printing method does not contain a binder resin, which is applied to the substrate in accordance with the shape of the wiring pattern, and then a conductor layer is generated by a conductor process.

International Publication No. 11/034019 Pamphlet

  Unlike a paste in which a conventional flaky metal is mixed with a resin binder, the printing method ink for forming the conductor layer is a metal nanoparticle dispersion containing no binder resin. The conductor layer such as the formed wiring has a problem of low adhesion to the substrate. In particular, it has been difficult to secure sufficient adhesive strength for inorganic materials such as inorganic plates such as glass and ceramics, and substrates with electrodes having oxide surfaces such as ITO and aluminum.

  Here, it is conceivable to add a resin to the printing method ink in order to improve the adhesive strength. However, when a resin is added to the printing method ink, the resin intervenes between the metal nanoparticles when making the conductor, preventing contact and fusion between the metal nanoparticles, resulting in a volume resistivity of the conductor layer. Increases and conductivity decreases.

  The present invention has been made in view of the above-mentioned background art, and is an ink for printing method having excellent adhesive strength between an inorganic material as a substrate and a conductor layer, a printed wiring board, a method for producing a printed wiring board, a display device, and a solar cell. The problem is to provide a module.

  Means for solving the above problems are as follows.

<1> An ink for printing method containing metal element-containing particles and 0.01% by mass or more and 10% by mass or less of zinc oxide particles in the total solid content.

<2> The printing method ink according to <1>, wherein the number average particle diameter of primary particles of the zinc oxide particles is 1 nm or more and 1000 nm or less.

<3> The particles according to <1> or <2>, wherein the metal element-containing particles include particles containing at least one selected from the group consisting of Cu, CuO, and Cu ₂ O, and further contain a dispersion medium. Ink for printing methods.

<4> an inorganic substrate;
A conductive layer that is a conductive layer of a printing method ink layer formed using the printing method ink according to any one of <1> to <3> provided on the inorganic substrate;
Printed wiring board having

<5> A step of forming a printing method ink layer by applying the printing method ink according to any one of <1> to <3> on an inorganic substrate;
A process of obtaining a conductive layer by subjecting the ink layer for printing method to a conductor; and
The manufacturing method of the printed wiring board which has this.

<6> The method for producing a printed wiring board according to <5>, wherein in the conductorization treatment, the ink layer for printing method is treated by heating to 120 ° C. or more in a gas containing formic acid.

<7> The method for producing a printed wiring board according to <6>, wherein the gas containing formic acid further contains an organic compound having a nitrogen-containing heterocyclic structure.

<8> The method for producing a printed wiring board according to any one of <5> to <7>, wherein the method of applying the printing method ink on the substrate is a method of applying the printing method ink in a pattern.

<9> The method for applying the pattern is selected from the group consisting of an inkjet method, a super inkjet method, screen printing, offset printing, jet printing, dispenser, needle dispenser, comma coat, slit coat, die coat, and gravure coat. The method for producing a printed wiring board according to <8>, wherein the method is performed by at least one method.

<10> A display device having the printed wiring board according to <4>.

<11> A solar cell module having the printed wiring board according to <4>.

  ADVANTAGE OF THE INVENTION According to this invention, the ink for printing methods which can form the electroconductive layer with improved adhesiveness with a board | substrate, a board | substrate with a transparent electrode, etc. can be provided. In addition, according to the present invention, it is possible to provide a printed wiring board, a printed wiring board manufacturing method, a display device, and a solar cell module in which both conductivity and adhesion between an inorganic material such as a substrate and a conductor layer are improved. it can.

In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. .
In the present specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
Further, in this specification, the amount of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means quantity.

<Ink for printing method>
The printing method ink of the present invention is a printing method ink for forming a conductor layer, and contains metal element-containing particles and 0.01% by mass to 10% by mass of zinc oxide particles in the total solid content. .
Zinc oxide has an affinity for an inorganic substrate that is an inorganic material, while metallic zinc is presumed to have an affinity for a conductor layer formed of metal element-containing particles. For this reason, it is estimated that the conductor layer formed from the ink for printing methods containing a metal element containing particle shows the outstanding adhesiveness with respect to an inorganic substrate.

  Note that the added zinc oxide particles are insulative, and as such, the conductive layer after the conductive treatment is hindered from being made conductive. However, it is possible to make the zinc oxide particles into a conductor by a conductor treatment described later, and this prevents the volume resistivity of the conductor layer from increasing and lowering the conductivity.

In addition, the ink for printing method of the present invention may not contain an insulating resin that is generally used for improving the adhesive strength. Therefore, resin does not intervene between metal element containing particles, and it can control that the conductivity of the formed conductor layer falls.
Hereinafter, components of the printing method ink of the present invention will be described in detail.

(Zinc oxide particles)
The zinc oxide particles according to the present invention are not particularly limited as long as they are particles containing zinc oxide. For example, particles of zinc oxide, and particles having a zinc oxide layer on at least a part of the surface of the particle core are metallic zinc. Zinc oxide particles may be used alone or in combination of two or more.

  The zinc oxide particles preferably have a primary particle number average particle size of 1000 nm or less, more preferably 500 nm or less, and even more preferably 100 nm or less, from the viewpoint of increasing the contact area with an inorganic material such as a conductor layer and a substrate.

  The lower limit of the number average particle size of the primary particles of the zinc oxide particles is not particularly limited, and is preferably 1 nm or more, more preferably 5 nm or more, and further preferably 10 nm or more from the viewpoint of producing particles.

  As a method for measuring the number average particle diameter of primary particles of zinc oxide particles, for example, when zinc oxide particles are aggregated to form secondary particles, a scanning electron micrograph (SEM) or a transmission electron microscope is used. There is a method in which the particle shape is directly observed by (TEM), the particle diameter of 50 primary particles is measured by image analysis, and the arithmetic average value is obtained.

  When the printing method ink is formed into a film by inkjet printing or inkjet coating, the maximum dispersed particle size of the zinc oxide particles in the printing method ink is preferably 10000 nm or less, more preferably 7000 nm or less, More preferably, it is 5000 nm or less.

  The maximum dispersed particle size of the zinc oxide particles was measured by a laser diffraction particle size distribution measuring device (LS13 320: manufactured by Beckman Coulter), a dynamic light scattering particle size distribution measuring device (N5, manufactured by Beckman Coulter). It is requested from.

  The content of the zinc oxide particles in the printing method ink is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on the solid content in the printing method ink, from the viewpoint of developing adhesiveness. 0.1 mass% or more is more preferable. Moreover, 10 mass% or less is preferable with respect to solid content in the ink for printing methods from the point of the conductor-conduction inhibitory effect of a zinc oxide, 5 mass% or less is more preferable, and 1 mass% or less is further more preferable.

  Examples of the shape of the zinc oxide particles include spherical, massive, needle-like or plate-like particles.

  In addition, the content of the zinc oxide particles with respect to the metal element-containing particles described later is preferably 0.01% by mass to 10% by mass, and 0.05% by mass to 5% by mass from the viewpoint of expression of conductivity and adhesiveness. More preferably, 0.1 mass%-2 mass% are further more preferable.

(Metal element-containing particles)
The ink for printing method of the present invention preferably contains metal element-containing particles for forming a conductor layer.
The metal element-containing particles may be particles of a metal or a compound containing a metal element as long as a metal layer can be formed by a conductor treatment described later. As such a metal element, an element that is not easily oxidized and is easily reduced to a metal in a conductor treatment is preferable, and examples thereof include gold, platinum, silver, palladium, iridium, copper, nickel, and the like, from Cu, CuO, and Cu ₂ O. It is preferable to include at least one selected from the group consisting of: The compound containing these metal elements may be any compound that can generate a metal by a conductor treatment, and an oxide, organic acid complex, carbonate, acetylacetone complex, hydroxide, nitride, nitrate of these metal elements. Etc.

  Examples of the shape of the metal element-containing particles include spherical, massive, needle-like, or plate-like particles. The number average particle diameter of the primary particles of the metal element-containing particles is preferably 1 nm to 1000 nm, more preferably 3 nm to 500 nm, and still more preferably 10 nm to 100 nm.

  The measurement method of the number average particle diameter of the primary particles of the metal element-containing particles is, for example, when the metal element-containing particles are aggregated to form secondary particles, a scanning electron micrograph (SEM) or transmission electron The method of directly observing a particle shape with a microscope (TEM) and performing the said measurement from image analysis is mentioned.

  When the printing method ink is formed by inkjet printing or inkjet coating, the maximum dispersed particle size of the metal element-containing particles in the printing method ink is preferably 1000 nm or less, more preferably 700 nm or less. More preferably, it is 500 nm or less.

  The maximum dispersed particle size of the metal element-containing particles is a particle size measured by a laser diffraction particle size distribution measuring device (LS13 320: manufactured by Beckman Coulter) or a dynamic light scattering particle size distribution measuring device (N5, manufactured by Beckman Coulter). It is obtained from the distribution.

  The content of the metal element-containing particles in the printing method ink is preferably 20% by mass or more, more preferably 40% by mass or more, and more preferably 50% by mass with respect to the solid content in the printing method ink in terms of conductivity. The above is more preferable. Moreover, 95 mass% or less is preferable with respect to solid content in the ink for printing methods from a viewpoint of applicability | painting, 94 mass% or less is more preferable, and 93 mass% or less is further more preferable.

(Dispersion medium)
The ink for printing method of the present invention preferably contains a dispersion medium from the viewpoint of applicability.
The dispersion medium that can be used is preferably a dispersion medium having a high dielectric constant from the viewpoint of dispersibility of the zinc oxide particles and the metal element-containing particles. Examples of such a dispersion medium include γ-butyrolactone, propylene carbonate, water, sulfolane, dimethylformamide, N-methylpyrrolidone, glycol sulfite, malononitrile, ethylene carbonate, acetone, phenylacetonitrile, acetonitrile, isophorone, and the like.

  The printing method ink is preferably adjusted to a viscosity suitable for each printing method when the printing method ink layer is formed by the printing method. Specifically, the dynamic viscosity at 25 ° C. is preferably 1 mPa · s to 400,000 mPa · s, and more preferably 5 mPa · s to 200,000 mPa · s. In particular, in the case of printing by inkjet printing, it is preferably 5 mPa · s to 20 mPa · s, and more preferably 8 mPa · s to 18 mPa · s.

The measurement of the dynamic viscosity of the printing method ink is performed using a viscoelasticity measuring apparatus (Physica MCR-501, manufactured by Anton Paar) at a shear rate of 0.5 s- ¹ . The dynamic viscosity is measured at 25 ° C., and the temperature raising operation is not performed.

<Method for producing conductor layer>
The manufacturing method of the printed wiring board using the ink for printing methods of this invention has the following processes at least.
(A) a step of applying the printing method ink on an inorganic substrate to form a printing method ink layer;
(B) A step of obtaining a conductive layer by subjecting the ink layer for printing method to a conductor treatment.

  Further, the step (A) may include a drying step after applying the printing method ink.

(Process (A))-Application process of ink for printing method-
[Preparation of ink for printing method]
The printing method ink preferably contains at least the zinc oxide particles and metal element-containing particles, and further contains the dispersion medium. In this case, the printing method ink is prepared by mixing the zinc oxide particles and metal element-containing particles in the dispersion medium. You may perform a dispersion | distribution process after mixing. Further, the maximum dispersed particle diameter of the zinc oxide particles and metal element-containing particles contained in the dispersion may be adjusted by classification.

  The distributed processing is performed using a disperser. Examples of such a disperser include an ultrasonic disperser, a thin-layer shear disperser, a bead mill, a high shear mixer, a liquid-liquid collision disperser, a high-speed rotating disperser using a centrifugal field, a roll mill, and a colloid mill.

  Classification can be performed using a classification device. Examples of such a classifier include a centrifugal separator, a filtration device, a cylindrical centrifugal sedimentation device, a decanter centrifugal sedimentator, a separation plate centrifugal sedimentator, and a coarse particle sedimentation operation by standing.

[Application of printing method ink]
A printing method ink layer is formed by applying a printing method ink on an inorganic substrate. Examples of the inorganic substrate according to the present invention include inorganic materials and substrates with electrodes.

  As the inorganic substrate applicable to the present invention, a material that can be bonded to zinc oxide is preferable. Specifically, glass, aluminum, copper, silver, gold, nickel, tin, lead, palladium, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Zinc Tin Oxide (ZTO), inorganic semiconductor, thermal oxide film Inorganic substrates formed from silicon nitride, boron nitride, silicon carbide and the like. Further, among the above, a plurality of materials may be patterned on the inorganic substrate.

  Examples of the method for applying the printing method ink include coating or printing. After forming the printing method ink, drying is preferably performed to eliminate fluidity.

As a method of applying the ink for printing method, a method such as spin coating, spray coating, ink jet coating, super ink jet, bar coating, gravure coating, knife coating, die coating, comma coating, slit coating, applicator, dip coating, etc. should be used. Can do.
As printing methods for printing ink for printing methods, methods such as ink jet printing, super ink jet printing, dispenser, needle dispenser, relief printing, intaglio printing, gravure printing, screen printing, jet printing method, transfer printing, offset printing, etc. are used. be able to.

  When the printing method ink is formed in a pattern, the method includes inkjet, super inkjet, screen printing, offset printing, jet printing, dispenser, needle dispenser, comma coat, slit coat, die coat, and gravure coat. Preferably it is at least one method selected from the group.

  The printing method ink layer formed by applying the printing method ink is preferably dried from the viewpoint of suppressing film thickness unevenness and contamination due to flow, and then proceeds to the next step.

  As the drying method, drying at room temperature, drying by heating, or drying under reduced pressure can be used. For heat drying or reduced pressure drying, hot plate, warm air dryer, warm air heating furnace, nitrogen dryer, infrared dryer, infrared heating furnace, far infrared heating furnace, microwave heating device, laser heating device, electromagnetic heating device A heater heating device, a steam heating furnace, a hot plate press device, or the like can be used.

  The temperature and time for drying are preferably adjusted as appropriate according to the type and amount of the dispersion medium used, and are preferably dried at 50 to 180 ° C. for 1 to 120 minutes, for example.

  The thickness of the printing method ink layer is desirably designed as appropriate according to the application (for example, wiring). Specifically, the average thickness of the conductor layer is preferably 0.1 μm to 32 μm, more preferably 0.3 μm to 20 μm, and still more preferably 0.5 μm to 12 μm.

The thickness of the ink layer for printing is measured as follows.
The ink layer for printing method was scratched with a cutter knife, and the depth of the scratch was measured using a three-dimensional non-contact surface shape measuring device (for example, Micromap MM3500, manufactured by Ryoka Systems Co., Ltd.), and the average was measured. The value is determined as the film thickness. Alternatively, the film thickness is determined by observing a conductive laminate subjected to trench processing with FIB at 45 ° with a scanning electron microscope (SEM) or a scanning ion microscope (SIM).

(Process (B)) -Conductive treatment-
Next, a conductive process is performed on the printing method ink layer. Use the following “heat treatment in the presence of formic acid gas” (gas phase method) from the point that the volume resistivity of the conductor layer after conductorization is low and that the densification progresses and the strength of the conductor layer itself is obtained. It is preferable to conduct the conductor.

(Gas phase method)
In the heating step in the presence of formic acid gas for making the ink layer for printing method into a conductor, the conductor is made by heating in a gas atmosphere containing formic acid gas. The formic acid gas is obtained by bringing a carrier gas into contact with liquid formic acid and saturating the carrier gas with formic acid, or by heating or depressurizing to 120 ° C. or higher in consideration of the boiling point of formic acid to form formic acid in a gaseous state. Preferably there is. For example, the method described in International Publication No. 11/034016 pamphlet can be adopted as the method for conducting the conductor by the vapor phase method.

  Note that the ink layer for printing method to which zinc oxide particles are added may not be easily made conductive and dense. However, by conducting the treatment in a treatment gas in which an organic compound having a gaseous nitrogen-containing heterocyclic structure is coexisted with gaseous formic acid, the conductor can be efficiently formed.

  Examples of the organic compound having such a nitrogen-containing heterocyclic structure include 2,2′-bipyridyl, 2,3′-bipyridyl, 6-methyl-2,2′-bipyridyl, 6,6′-dimethyl-2,2 '-Bipyridyl, 5,5'-dimethyl-2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, 6-bromo-2,2'-bipyridyl, 4,4'-dimethoxy- 2,2′-bipyridyl, 2,3′-bipyridyl, 4,5-diazafluorene, 2,2 ′: 6 ′, 2 ″ -terpyridine, bipyridyl and terpyridines such as 2,2′-bipyrimidine; pyridine, 2-methylpyridine, 4-methylpyridine, 2,4-lutidine, 2-methoxypyridine, 3-methoxypyridine, 4-methoxypyridine, 2,6-dimethoxypyridine, 2-chloropyridine, 3-chloro Lysine, 4-chloropyridine, 2-fluoropyridine, 3-fluoropyridine, 4-fluoropyridine, 2-bromopyridine, 3-bromopyridine, 4-bromopyridine, 2-phenylpyridine, 3-phenylpyridine, 4-phenyl Pyridines such as pyridine, 2,6-diphenylpyridine, 5-methylpyridine-3-carbonitrile; Quinolines such as quinoline, isoquinoline, benzoquinoline, 2- (2-pyridinyl) quinoline; Pyridazine, pyrimidine, pyrazine, etc. Diazines; quinoxalines such as quinoxaline, phthalazine, quinazoline, cinnoline; phenanthrolines such as 1,10-phenanthroline, 4,7-phenanthroline, 1,7-phenanthroline; triazine, acridine, naphthyridine, benzoxazole, benzo Azole, carbazole, pyrrole, indole, purine and the like.

  The amount of the organic compound having a nitrogen-containing heterocyclic structure with respect to formic acid is preferably 0.1 mol% to 40 mol%, more preferably 0.5 mol% to 10 mol%, and 1 mol% to 5 mol%. More preferably.

<Printed wiring board>
By the method for producing a printed wiring board of the present invention, a printed wiring board having high adhesion between the conductive layer and the inorganic substrate and having electrical continuity between the conductive layer and the electrode can be produced.
The printed wiring board of the present invention includes an inorganic substrate and a conductive layer that is a conductive layer of the printing method ink layer formed by the printing method ink provided on the inorganic substrate.

<Use of printed wiring board>
The printed wiring board can be used in liquid crystal displays, organic EL displays, touch panels, display devices such as electronic paper, matrix sensor arrays, solar cell modules, and the like. The obtained display device, matrix sensor array, and solar cell module have high adhesion between the conductor layer and the substrate, can adhere and conduct between the wiring and the electrode, and can have high conductivity.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Example 1]
(Preparation of ink for printing method)
Zinc oxide particles (primary particle number average particle size 100 nm, manufactured by CIK Nanotech) 0.165 g and copper oxide nanoparticles (primary particle volume average particle size 70 nm, manufactured by CIK Nanotech) 32.835 g were mixed with propylene carbonate (Wako Pure) The mixture was mixed with 27 g of Yakuhin Kogyo Co., Ltd. and treated with an ultrasonic homogenizer (US-600, manufactured by Nippon Seiki Co., Ltd.) at 19.6 kHz, 600 W for 3 minutes to prepare a printing method ink. The dynamic viscosity of the printing method ink at a shear rate of 0.5 s ⁻¹ at 25 ° C. was 10 mPa · s.

(Formation of ink layer for printing method)
A glass preparation was used as the substrate. The substrate was washed by immersing the substrate in sodium hydroxide saturated isopropanol for 10 minutes, then immersing it in ultrapure water three times, and then drying.
The prepared printing method ink is applied onto the washed glass preparation with an applicator having a gap of 100 μm, heated from 50 ° C. to 160 ° C. in 20 minutes with a hot air dryer, and then dried at 160 ° C. for 10 minutes. A printed wiring board precursor having an ink coating layer (printing method ink layer) formed thereon was obtained.

  Part of the obtained ink layer for printing method is shaved, the surface shape is measured with a laser interference type surface shape measuring device, and the difference in height between the average value of the surface of the ink layer for printing method and the substrate surface is obtained and printed. It was 2.3 μm when measured as the thickness of the legal ink layer.

(Conductor treatment)
2,3′-bipyridyl (2.85 g, 3 mol%) was dissolved in formic acid (27.15 g) to obtain a conductor treatment solution. The printed wiring board precursor was set on an aluminum plate having a thickness of 5 mm on the bottom of a flat bottom separable flask heated in an oil bath. An aluminum cup was placed on the aluminum plate, and the conductive treatment solution was fed into the aluminum cup at 0.030 ml / min through a Teflon (registered trademark) tube having a diameter of 1 mm by a syringe pump, and was vaporized by heating. A chromel alumel thermocouple was set on the glass preparation used for the printed wiring board precursor and set on an aluminum plate, and the temperature of the conductive laminate precursor was measured.

  Heating was performed in an oil bath at 195 ° C. while flowing nitrogen at 0.3 L / min through a separable flask in which the printed wiring board precursor was set. After the temperature of the printed wiring board precursor became constant (180 ° C.), feeding of the conductor treatment liquid was started. After treating for 60 minutes, it was kept at 180 ° C. for 10 minutes while flowing only nitrogen, and then the separable flask was allowed to cool, and after the printed wiring board became 50 ° C. or less, the printed wiring board was taken out into the air.

(Resistance measurement)
The surface resistivity of the printed wiring board was measured using a four-probe method low resistivity meter (Loresta-GP, manufactured by Mitsubishi Chemical Corporation) and found to be 0.25Ω / □.

(Tape peeling test)
The copper layer of the obtained printed wiring board had a dense layer having metallic luster on the substrate side and a brittle powdery layer on the surface. The surface powder was removed by rubbing lightly with Kim Towel (registered trademark, manufactured by Nippon Paper Crecia) to prepare a sample for tape peeling test, and the following tape peeling test was performed.
Cellotape (registered trademark) (manufactured by Nichiban, trade name) was attached to the copper layer side of the sample for tape peeling test, and was sufficiently adhered with fingers and then peeled off. As a result, 100 area% of the copper layer to which the tape was attached remained on the substrate side. This judged that there was good adhesiveness.

[Example 2]
Resistance measurement and a tape peeling test were performed in the same manner as in Example 1 except that 0.33 g of zinc oxide particles and 32.67 g of copper oxide nanoparticles were used. The surface resistivity of the printed wiring board was 0.056Ω / □. In the tape peeling test, it was judged that there was good adhesion without peeling.

[Example 3]
A resistance measurement and a tape peeling test were performed in the same manner as in Example 1 except that 1.65 g of zinc oxide particles and 31.35 g of copper oxide nanoparticles were used. The surface resistivity of the printed wiring board was 1.38Ω / □. In the tape peeling test, it was judged that there was good adhesion without peeling.

[Comparative Example 1]
A resistance measurement and a tape peeling test were performed in the same manner as in Example 1 except that 33 g of copper oxide nanoparticles were used without using zinc oxide particles. The surface resistivity of the printed wiring board was 0.22Ω / □. In the tape peeling test, the entire conductor layer peeled from the substrate surface, and there was no adhesion.

Claims (11)

  A printing method ink comprising metal element-containing particles and zinc oxide particles having a total solid content of 0.01% by mass or more and 10% by mass or less.   The ink for printing methods according to claim 1, wherein the number average particle diameter of primary particles of the zinc oxide particles is 1 nm or more and 1000 nm or less. 3. The printing method ink according to claim 1, wherein the metal element-containing particles include particles containing at least one selected from the group consisting of Cu, CuO, and Cu ₂ O, and further contain a dispersion medium. . An inorganic substrate;
A conductive layer that is a conductive layer of the printing method ink layer formed by the printing method ink according to any one of claims 1 to 3 provided on the inorganic substrate;
Printed wiring board having Applying the printing method ink according to any one of claims 1 to 3 onto an inorganic substrate to form a printing method ink layer;
A process of obtaining a conductive layer by subjecting the ink layer for printing method to a conductor; and
The manufacturing method of the printed wiring board which has this.   The method for producing a printed wiring board according to claim 5, wherein in the conductorization treatment, the ink layer for printing method is treated by heating to 120 ° C. or more in a gas containing formic acid.   The method for producing a printed wiring board according to claim 6, wherein the gas containing formic acid further contains an organic compound having a nitrogen-containing heterocyclic structure.   The method for producing a printed wiring board according to any one of claims 5 to 7, wherein the method of applying the printing method ink on the substrate is a method of applying the printing method ink in a pattern.   The method of applying the pattern is at least selected from the group consisting of an inkjet method, a super inkjet method, screen printing, offset printing, jet printing printing, dispenser, needle dispenser, comma coat, slit coat, die coat, and gravure coater. The manufacturing method of the printed wiring board of Claim 8 performed by one method.   A display device comprising the printed wiring board according to claim 4.   The solar cell module which has a printed wiring board of Claim 4.