JP7117047B2 - Method for forming metal wiring - Google Patents

Description

The present invention relates to a method of forming metal wiring on a substrate.

In recent years, printed electronics have been developed as wiring technology for semiconductor elements, electronic circuits, and the like (see, for example, Non-Patent Document 1, Non-Patent Document 2, Non-Patent Document 3, and Patent Document 1). Printed electronics have attracted attention because they can reduce manufacturing costs compared to existing semiconductor manufacturing techniques such as photolithography.

According to Non-Patent Document 1, for example, FIG. 1 (1), a hydrophobic polyethylene naphthalate (PEN) substrate is irradiated with vacuum ultraviolet rays having a wavelength of 185 nm through a mask to make the irradiated portion hydrophilic, It discloses that a silver colloidal ink is applied to form a silver wiring.

According to Non-Patent Document 1, for example, FIG. It discloses that vacuum ultraviolet rays having a wavelength of 185 nm are irradiated through the substrate to make the irradiated portion hydrophilic, then colloidal silver ink is applied, and silver wiring is formed.

According to FIG. 2 of Non-Patent Document 2, Cytop, which is a fluorine-containing polymer, is formed by coating, and the surface is irradiated with vacuum ultraviolet rays with a wavelength of 172 nm through a mask to make the irradiated site hydrophilic. It discloses that a gold colloidal ink is applied to form a gold wiring.

According to FIGS. 1 and 2 of Non-Patent Document 3, a PEN substrate is vapor-deposited with hydrophobic parylene by chemical vapor deposition (CVD), irradiated with vacuum ultraviolet rays having a wavelength of 150 to 200 nm through a mask, It discloses that gold colloidal ink is applied after making the irradiated area hydrophilic, and gold wiring is formed.

However, although Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3 all disclose techniques for controlling the wettability of hydrophobic materials and performing metal wiring, there are the following problems. When the PEN substrate of Non-Patent Document 1 is used, only two-dimensional metal wiring can be obtained, and another technique must be employed to obtain three-dimensional metal wiring. When CYTOP of Non-Patent Document 2 is used as a hydrophobic material, the CYTOP surface does not have lipophilicity, so there is a significant limitation in subsequent processes. When SAM of Non-Patent Document 1 or Parylene of Non-Patent Document 3 is used as a hydrophobic material, an expensive apparatus such as CVD is required. It would be desirable to be able to apply hydrophobic and lipophilic materials by simpler techniques such as coating.

According to Patent Document 1, a step of forming on a substrate a first wettability changing layer containing a material whose surface energy changes when energy is applied; forming a first conductive layer on the property changeable layer; and forming a second wettability changeable layer on the first wettability changeable layer on which the first conductive layer is formed and containing a material whose surface energy changes when energy is applied. forming a wettability variable layer, and forming recesses that will become the wiring pattern of the second conductive layer in the second wettability variable layer by a laser ablation method using a laser with a wavelength in the ultraviolet region, After forming a high surface energy region by changing the surface energy of the surface of the second wettability changing layer exposed by forming the recess, a via hole is formed so as to partially expose the first conductive layer, and the via hole is formed. forming a high surface energy region by changing the surface energy of the surface of the second wettability changeable layer exposed by the formation of the second conductive layer and vias by applying a conductive ink to the high surface energy region; A method of forming a laminated wiring is disclosed, which includes the step of forming simultaneously. In particular, Patent Document 1 uses an NMP solution of thermosetting polyimide as the first wettability variable layer and an NMP solution of polyimide containing a dendrimer in the side chain as the second wettability variable layer, and applies them by spin coating. In addition to these, polyamideimide, a polymer of (meth)acrylic acid, and the like are disclosed.

However, in Patent Document 1, the film thickness is reduced by laser ablation, the process takes a long time, and wiring having a narrow line width of less than 10 μm cannot be obtained, and further improvements are required. ing.

JP 2015-015378 A

Masataka Kano et al., Appl. Phys. Express 3 (2010) 051601 Takeo Minari et al., Adv. Funct. Mater. 2014, 24, 4886-4892 Xuying Liu et al., Adv. Mater. 2016, 28, 6568-6573

As described above, an object of the present invention is to provide a method for easily forming a metal wiring having a line width of 10 μm or less, further less than 10 μm, and is applicable not only to two dimensions but also to large areas. An object of the present invention is to provide a method for forming a three-dimensional metal wiring having a line width of 10 μm or less using a simple coating technique.

A method for forming a metal wiring according to the present invention comprises a step of forming a wettability control layer on a substrate, wherein at least one selected from the group consisting of cycloolefin polymer, polylactic acid and derivatives thereof, and polysilazane. applying a polymer solution containing a polymer material to the substrate and drying it; irradiating the wettability control layer with vacuum ultraviolet rays having a wavelength of 200 nm or less; and applying a metallic ink to the substrate, thereby solving the above problem.
The metal ink may be a composition in which metal nanoparticles are dispersed in a dispersion medium.
The metal nanoparticles are gold (Au), silver (Ag), copper (Cu), platinum (Pt), iron (Fe), nickel (Ni), tin (Sn), zinc (Zn), lead (Pb) , palladium (Pd), aluminum (Al), and alloys thereof, and the dispersion medium may contain at least water.
A content of the water in the dispersion medium may be 80% by volume or more.
The vacuum ultraviolet rays may have a wavelength in the range of 150 nm or more and 200 nm or less.
The vacuum ultraviolet rays may have irradiation energy in the range of 1 mW/cm ² or more and 100 mW/cm ² or less.
The step of irradiating the vacuum ultraviolet rays may irradiate the vacuum ultraviolet rays for 5 seconds or more and 1000 seconds or less.
The step of irradiating the vacuum ultraviolet rays may use a photomask or a metal mask.
A concentration of the metal nanoparticles in the metal ink may range from 1 wt % to 60 wt %.
In the step of applying the metal ink, the application is performed by a spin coating method, a spray coating method, a dip coating method, a slit coating method, a slot coating method, a bar coating method, a roll coating method, a curtain coating method, an inkjet method, and, It may be done by a technique selected from the group consisting of screen printing.
The step of applying the metal ink may apply the metal ink on the wettability control layer and dry it.
In the step of forming the wettability control layer, the coating is performed by a spin coating method, a spray coating method, a dip coating method, a slit coating method, a slot coating method, a bar coating method, a roll coating method, a curtain coating method, an inkjet method, and a technique selected from the group consisting of screen printing.
In the step of forming the wettability control layer, the drying may be performed by heating the applied polymer solution in a temperature range of 30°C or higher and 200°C or lower.
The concentration of the polymer material in the polymer solution may range from 0.1 wt % to 50 wt %.
The concentration of the polymer material in the polymer solution may range from 0.5 wt % to 30 wt %.
Solvents for the polymer solution include xylene, hexafluoro-2-propanol, benzene, toluene, mesitylene, cyclohexane, dichloromethane, chloroform, carbon tetrachloride, propylene glycol monomethyl ether acetate, methyl ether, ethyl ether, propyl ether, and At least one may be selected from the group consisting of butyl ether.
A step of forming a further wettability control layer following the step of applying the metal ink, wherein at least one selected from the group consisting of a cycloolefin polymer, polylactic acid and derivatives thereof, and polysilazane. a step of applying a polymer solution containing a polymer material onto the wettability control layer and the metal wiring obtained by applying the metal ink and drying the polymer solution; and forming recesses in the further wettability control layer. , exposing at least part of the metal wiring, irradiating the further wettability control layer with vacuum ultraviolet rays having a wavelength of 200 nm or less, and applying a metal ink on the further wettability control layer and the recess. may further include the step of:
The exposing step may irradiate with an ultraviolet laser.
The step of forming the additional wettability control layer, the step of exposing, the step of irradiating, and the step of repeating the coating may be further included.
A step of peeling the wettability control layer from the substrate may be further included.

A method for forming a metal wiring according to the present invention includes the steps of forming a wettability control layer on a substrate, irradiating the wettability control layer with vacuum ultraviolet rays having a wavelength of 200 nm or less, and forming a metal on the wettability control layer. and applying the ink. The wettability control layer contains at least one polymeric material selected from the group consisting of cycloolefin polymer, polylactic acid, derivatives thereof, and polysilazane among various hydrophobic polymeric materials. It can be easily obtained by simply applying a polymer solution. By irradiating this with vacuum ultraviolet rays having a wavelength of 200 nm or less, it is possible to clarify the difference in wettability between the ultraviolet-irradiated portion and the non-irradiated portion. As a result, a hydrophilic region having a line width of 10 μm or less can be formed, and a thin metal wire having a line width of 10 μm or less can be formed. In addition, since the wettability control layer made of the polymer material described above has not only hydrophobicity but also lipophilicity, various layers can be formed thereon by a coating method using an organic solvent. According to the method of the present invention, the wettability control layer can be applied by an existing coating method without using a special device, so that the manufacturing cost can be suppressed.

In addition, in the method for forming a thin metal wire of the present invention, depending on the selection of the polymeric material that constitutes the wettability control layer, the wettability control layer on which the metal wiring is formed can be peeled off from the substrate, so it can be applied to wearable devices.

By adopting the method for forming fine metal wires of the present invention, not only two-dimensional but also three-dimensional fine metal wire patterns can be provided, so three-dimensional flexible wiring boards can also be provided at low cost.

1 is a flow diagram illustrating steps in a method for forming metal interconnects of the present invention; FIG. It is a schematic diagram which shows the procedure which forms the metal wiring of this invention. FIG. 4 is a flow diagram illustrating steps of a further method of forming metal interconnects of the present invention; FIG. 4 is a schematic diagram showing a further procedure for forming metal wiring of the present invention; 4 is an optical microscope image showing metal wiring of Example 1. FIG. 4 is an optical microscope image showing metal wiring of Example 2. FIG. 4 is an FTIR spectrum of the wettability control layer of Example 11. FIG. (1) is the spectrum of the wettability control layer after applying the polymer solution to the PEN substrate, and (2) is the spectrum of the wettability control layer after drying. 11 is a spectrum showing the measurement results of the light transmittance of the wettability control layer (SiO ₂ film) of Example 11. FIG. 11 is an AFM image of the wettability control layer (SiO ₂ film) of Example 11. FIG. (a) TEM image of a wettability control layer (SiO ₂ film) formed on a Si wafer. (b) SAED patterns obtained for two regions of the same field of view as (a). FIG. 10 is a schematic diagram showing the step of forming a three-layer structure wettability control layer (SiO ₂ film) (right side) of Example 16 on a PEN substrate (left side). FIG. 10 is a diagram showing the analysis results of the wettability control layer (SiO ₂ film) of Example 16 with a scanning white light interference microscope. 17 is an optical microscope image showing the metal wiring of Example 17. FIG. (a) is an optical microscope image showing the metal wiring of Example 18; (b) Enlarged image of the portion surrounded by the dotted line in (a). (c) It is a schematic diagram which shows the structure of the part shown to (b).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code|symbol is attached|subjected to the same element and the description is abbreviate|omitted.

(Embodiment 1)
Embodiment 1 describes a method for forming two-dimensional metal wiring on a substrate according to the present invention.
FIG. 1 is a flow diagram showing the steps of the method for forming metal interconnects of the present invention.
FIG. 2 is a schematic diagram showing the procedure for forming the metal wiring of the present invention.

Each step will be described in detail with reference to FIGS.
Step S110: forming the wettability control layer 220 on the substrate 210; Specifically, a polymer solution containing at least one polymer material selected from the group consisting of a cycloolefin polymer, polylactic acid, derivatives thereof, and polysilazane is applied to the substrate 210, dried, and selected. A wettability control layer 220 made of a polymer material is formed.

The material of the substrate 210 is not limited as long as the wettability control layer 220 is formed thereon, but polymer substrates, Si wafers, glass, metal plates, paper, and the like can be used. Polymer substrates may include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyimide, polycarbonate, polyethersulfone, polyethylene, and (meth)acrylic resins. As for paper, in addition to those using general wood pulp as a raw material, there are those using cellulose nanofiber as a raw material (cellulose nanopaper), and the like. The substrate is not limited to a plate shape, and may have a curved surface. Also, the substrate may be a self-supporting film. A base layer such as a semiconductor film, a metal film, a dielectric film, or an organic film may be formed on the surface of the substrate.

The wettability control layer 220 preferably has hydrophobicity and lipophilicity. As a result, a new layer (for example, a further wettability control layer to be described later) can be formed on the wettability control layer 220, so that a three-dimensional structure can be produced. In the present specification, "having hydrophobicity and having lipophilicity" means having wettability when anisole, which is one of typical organic solvents, is added dropwise. Having wettability here means that the static contact angle of anisole at room temperature is 0°≦θ≦30°.

The wettability control layer 220 preferably has a thickness in the range of 10 nm or more and 1000 μm or less. If the thickness is within this range, the film can be easily formed by coating. The wettability control layer 220 more preferably has a thickness in the range of 100 nm or more and 100 μm or less. As a result, wettability can be controlled by irradiation with vacuum ultraviolet rays, which will be described later. The wettability control layer 220 still more preferably has a thickness in the range of 100 nm to 10 μm. As described above, the polymer material constituting the hydrophobic and lipophilic wettability control layer 220 is at least one selected from the group consisting of cycloolefin polymer, polylactic acid, derivatives thereof, and polysilazane. Species selected.

By cycloolefin polymer is intended a resin obtained by polymerizing cycloolefin monomers. Examples of cycloolefin monomers include bicyclics such as norbornene and norbornadiene; tricyclics such as dicyclopentadiene and hydroxydicyclopentadiene; tetracyclics such as tetracyclododecene; Pentacyclics, heptacyclics such as tetracyclopentadiene, or derivatives thereof. Derivatives include alkyl (methyl, ethyl, propyl, butyl, etc.)-substituted products, alkenyl (vinyl, etc.)-substituted products, alkylidene (ethylidene, etc.)-substituted products, aryl (phenyl, tolyl, naphthyl, etc.)-substituted products, and the like. . Moreover, any one of these may be a homopolymer, or a copolymer obtained by combining two or more thereof may be used.

Polylactic acid intends resins obtained by polymerizing L-lactic acid, D-lactic acid or derivatives thereof. Specifically, polylactic acid may be a homopolymer of L-lactic acid or D-lactic acid, a copolymer of L-lactic acid and D-lactic acid, or a copolymer of these homopolymers. It may be a mixture with a copolymer. Derivatives include alkyl (methyl, ethyl, propyl, butyl, etc.)-substituted products, alkenyl (vinyl, etc.)-substituted products, alkylidene (ethylidene, etc.)-substituted products, aryl (phenyl, tolyl, naphthyl, etc.)-substituted products, and the like. .

By polysilazane is intended a polymeric compound having Si--N--Si bonds. Specifically, polysilazane is a polymer having a repeating unit of the formula: -[Si(R ₁ )(R ₂ )-N(R ₃ )]-. be. The polysilazane may be an inorganic polysilazane in which all of R ₁ , R ₂ and R ₃ are hydrogen atoms in the above formula, or an organic polysilazane in which at least one of R ₁ , R ₂ and R ₃ is a group other than a hydrogen atom. may be The former is also called perhydropolysilazane (PHPS), and the latter is also called organopolysilazane. Examples of organopolysilazanes include polymethylhydrosilazane (PMHS), poly-N-methylsilazane, poly-N-(triethylsilyl)allylsilazane, poly-N-(dimethylamino)cyclohexylsilazane, and phenylpolysilazane. One kind of polysilazane may be used, or a mixture of two or more kinds may be used.

A polymer solution is prepared by dissolving these polymer materials in any solvent that dissolves them. Solvents include, but are not limited to, xylene, hexafluoro-2-propanol, benzene, toluene, mesitylene, cyclohexane, dichloromethane, chloroform, carbon tetrachloride, propylene glycol monomethyl ether acetate, methyl ether, ethyl ether, propyl ether, and , butyl ether. These solvents are readily available and can dissolve the polymeric materials described above.

The concentration of the polymer material in the polymer solution is preferably in the range of 0.1 wt % or more and 50 wt % or less. By setting it as this range, application|coating becomes easy. More preferably, the concentration of the polymeric material ranges from 0.5 wt% to 30 wt%. By setting the thickness within this range, the wettability control layer 220 having the thickness described above can be formed. Even more preferably, the concentration of the polymeric material ranges from 5 wt% to 25 wt%. In addition, when two or more kinds of polymer materials are used, the total concentration thereof should be within the above range.

Application of the polymer solution to the substrate 210 is not particularly limited as long as it can form a film, but examples include spin coating, spray coating, dip coating, slit coating, slot coating, bar coating, and roll coating. A method selected from the group consisting of a coating method, a curtain coating method, an inkjet method, and a screen printing method is employed. By using these, a uniform wettability control layer 220 can be formed. Among them, the spin coating method is preferable because it is simple.

The wettability control layer 220 can be obtained by drying the polymer solution applied to the substrate 210. The drying is preferably performed by heating in the temperature range of 30°C or higher and 200°C or lower. Thereby, a uniform wettability control layer 220 is obtained. Drying is more preferably carried out by heating in the temperature range of 40°C or higher and 100°C or lower. Although there is no time limit for drying, drying may be performed for 1 minute or more and 24 hours or less. A hot plate, a constant temperature bath, an oven, or the like can be used for drying. In addition, drying may be performed several times under different conditions as needed. For example, after pre-drying for 1 minute or more and 10 minutes or less in the above preferred temperature range, main drying may be performed for 10 minutes or more and 24 hours or less in the same temperature range. Such predrying can suppress the formation of pores and cracks when the solvent is removed from the polymer solution, and a more uniform wettability control layer 220 can be obtained. Drying may also be carried out under controlled relative humidity conditions, if desired. Examples of relative humidity include a range of 40% RH or less, a range of 40% RH or more and 70% RH, a range of 70% RH or more and 90% RH or less, and 90% RH or more. For example, when polysilazane is used as the polymer material, the crosslinking reaction of polysilazane proceeds with water molecules as a catalyst by drying under wet conditions of 90% RH or higher, and a SiO ₂ film is formed as the wettability control layer 220 . can get. In order to control the relative humidity, a humidity-adjustable oven may be used, or a hot plate, a constant temperature bath, or the like may be used in an environment in which the relative humidity can be measured.

Step S120: The wettability control layer 220 is irradiated with vacuum ultraviolet rays having a wavelength of 200 nm or less. As a result, the wettability control layer 220 becomes hydrophilic only at the portion 230 irradiated with the vacuum ultraviolet rays.

Usually, a photomask, metal mask, or the like having a predetermined opening corresponding to the shape of a metal wiring pattern is placed on the wettability control layer 220 . As a result, a portion 230 irradiated in a pattern corresponding to the metal wiring pattern is obtained. Note that the patterned portion 230 becomes hydrophilic as described later, so it may be called a wettability changing film formed in the wettability control layer 220 . If the method of the present invention is adopted, a metal wiring having a line width of 10 .mu.m or less can be formed, so a photomask or metal mask having an opening of 10 .mu.m or less can be used.

The vacuum ultraviolet rays preferably have a wavelength of 150 nm or more and 200 nm or less. An argon fluoride laser emitting a wavelength of 193 nm, a xenon excimer lamp emitting a wavelength of 172 nm, a fluorine laser emitting a wavelength of 157 nm, or the like can be used as a light source for emitting such vacuum ultraviolet rays. By irradiating the light having these energies, the polymer material constituting the wettability control layer 220 becomes hydrophilic because only the irradiated portion 230 is broken. The vacuum ultraviolet rays preferably have a wavelength of 160 nm or more and 180 nm or less. With energy in this range, only the efficiently irradiated portion 230 can be rendered hydrophilic.

Furthermore, these vacuum ultraviolet rays preferably have irradiation energy in the range of 1 mW/cm ² or more and 100 mW/cm ² or less. As a result, the bond of the polymer material in the portion 230 irradiated with light can be cut. More preferably, the vacuum ultraviolet rays have irradiation energy in the range of 5 mW/cm ² or more and 40 mW/cm ² or less.

The irradiation time of the vacuum ultraviolet rays is in the range of 5 seconds to 1000 seconds. As a result, the bond of the polymer material in the portion 230 irradiated with light is cut, and the surface can be modified to have a hydrophilic surface. The irradiation time is more preferably in the range of 15 seconds to 600 seconds, and even more preferably in the range of 30 seconds to 150 seconds.

Step S<b>130 : Applying a metal ink on the wettability control layer 220 . As a result, the metal ink remains only on the hydrophilic portion 230 on the wettability control layer 220 , which becomes the metal wiring 240 . The thickness of the metal wiring 240 is preferably in the range of 30 nm or more and 5000 nm or less. Thereby, it functions as a metal wiring.

Application of the metal ink to the hydrophilic portion 230 is not particularly limited as long as the film can be formed. Examples include spin coating, spray coating, dip coating, slit coating, slot coating, and bar coating. method, roll coating method, curtain coating method, inkjet method, and screen printing method are employed. By using these, the metal wiring 240 having a uniform thickness can be formed. Among them, the slit coating method is preferable because it is simple.

The metal ink is a composition in which metal nanoparticles are dispersed in a dispersion medium, and is not particularly limited as long as it can be located only at hydrophilic sites, but gold (Au) and silver (Ag) are preferred. , copper (Cu), platinum (Pt), iron (Fe), nickel (Ni), tin (Sn), zinc (Zn), lead (Pb), palladium (Pd), aluminum (Al), and their It contains metal nanoparticles selected from the group consisting of alloys and a dispersion medium containing at least water.

In the specification of the present application, the metal nanoparticles are intended to mean particles made of the above-mentioned metals and having a particle size in the range of 1 nm or more and 1 μm or less. The particle size is measured by, for example, a laser diffraction/scattering method (microtrack method). Preferably, the metal nanoparticles have a particle size in the range of 1 nm to 100 nm, more preferably in the range of 10 nm to 50 nm.

The metal ink is a composition in which metal nanoparticles are dispersed in a dispersion medium containing at least water, but in addition to water, they may be dispersed in alcohols such as methanol, ethanol and isopropanol. The content of water in the dispersion medium is preferably 80% by volume or more. As a result, the metal ink can be selectively positioned only on the hydrophilic portion 230, resulting in a metal wiring having a line width of 10 μm or less.

The concentration of metal nanoparticles in the metal ink is preferably in the range of 1 wt % or more and 60 wt % or less. Within this range, the metal wiring 240 can be obtained. The concentration of metal nanoparticles is more preferably in the range of 15 wt % or more and 25 wt % or less. This results in the metal wiring 240 having the thickness described above.

The metallic ink may further contain organic additives such as binders and ligands. A binder is advantageous in controlling the viscosity of the metal ink, and examples thereof include glycerin, propylene glycol, and the like. A ligand is provided to disperse the metal nanoparticles in a dispersion medium, and examples thereof include alkyl compounds, phthalocyanines, porphyrins, and the like.

When the content of the above-described organic additive is small (for example, 1 wt % or less), metal nanoparticles such as gold, silver, and copper are densely arranged just by coating, and easily form metal wiring. On the other hand, when the content of the above-mentioned organic additives is large (for example, exceeds 1 wt%), or when the surface of the metal nanoparticles is oxidized, baking by heating or light baking using a flash lamp etc. may be performed. Thereby, metal wiring can be easily formed.

As described above, when the content of the organic additive in the applied metal ink is 1 wt % or less, the amount of coating to form a thin line is extremely small, so air drying is easy, and the organic additive is removed. Since the content is small, conductivity is exhibited even without removing the organic additive, so drying by heating or the like is not essential. However, the metal ink applied to the portion 230 may be dried by heating, light baking, or the like. As a result, the dispersion medium and the organic additive in the metal ink can be fired and removed, and the metal nanoparticles can be sintered together. Natural drying may be used, but gold and silver may be heated to a temperature of 60° C. or higher and 200° C. or lower, and copper may be heated to a temperature of 80° C. or higher and 300° C. or lower. A hot plate, a photobaking machine, a constant temperature bath, or the like can be used for drying.

In this manner, two-dimensional metal wiring can be formed on the substrate. In particular, when the wettability control layer 220 has the thickness of a self-supporting film, the wettability control layer 220 may be peeled off from the substrate 210 . This allows electronic circuits to be fabricated on extremely thin substrates.

(Embodiment 2)
Embodiment 2 describes a method for forming three-dimensional metal wiring on a substrate according to the present invention.
FIG. 3 is a flow diagram illustrating additional method steps for forming metal interconnects of the present invention.
FIG. 4 is a schematic diagram showing a further procedure for forming the metal wiring of the present invention.

Each step will be described in detail with reference to FIGS. This is performed subsequent to step S130 in the first embodiment.

Step S310: Following step S130, a further wettability control layer 410 is formed on the two-dimensional metal wiring. Again, a polymer solution containing at least one polymer material selected from the group consisting of cycloolefin polymer, polylactic acid, derivatives thereof, and polysilazane is applied to wettability control layer 220 and metal ink. is applied onto the metal wiring 240 obtained by the above and dried. Since the specific conditions are the same as those in step S110 described with reference to FIGS. 1 and 2, description thereof is omitted.

Step S320: forming recesses 420 in the further wettability control layer 410 to expose at least a portion of the metal wiring 240; Any means that can mechanically or chemically etch the further wettability control layer 410 can be used to form the recesses 420, but preferably an ultraviolet laser with a wavelength of 250 nm or more and 550 nm or less may be applied. Examples of such ultraviolet lasers include YAG lasers. As a result, the bond of the polymer material in the portion 420 irradiated with light can be cut.

In the present invention, since the ultraviolet laser is irradiated only to the portions that are to become the recesses, the wettability control layer 410 other than the recesses 420 is not scraped to form steps. In addition, since the ultraviolet laser only needs to be applied to the portions to be recessed portions, the processing time can be shortened.

It should be noted that an electrode pad may be formed in advance in a portion that is normally to be a concave portion. Such electrode pads use a mask having electrode pad-shaped openings when irradiating the wettability control layer 220 with vacuum ultraviolet rays having a wavelength of 200 nm or less in step S120, and apply metal ink in step S130. By doing so, electrode pads are formed.

Step S330: A vacuum ultraviolet ray having a wavelength of 200 nm or less is irradiated to an arbitrary area on the further wettability control layer 410 where an electric wiring is to be formed. At this time, the region irradiated with the vacuum ultraviolet rays includes a concave portion 420 formed in the wettability control layer 410 . As a result, the further wettability control layer 410 becomes hydrophilic only at the portion 430 irradiated with the vacuum ultraviolet rays. Here, too, the portions 430 are irradiated in a pattern corresponding to the metal wiring pattern. In addition, since the patterned portion 430 is hydrophilic, it may be called a further wettability changing film formed in the further wettability control layer 410 . Since step S330 is the same as step S120 described with reference to FIGS. 1 and 2, description thereof is omitted.

Step S<b>340 : Coat a metal ink on the further wettability control layer 410 and the recesses 420 . Step S340 is the same as step S130 described with reference to FIGS. 1 and 2, except that the metal ink is also applied to the concave portion 420, so description thereof will be omitted.

When the metal ink is applied, the metal ink remains only on the hydrophilic portion 430 and the concave portion 420 on the further wettability control layer 410 . As a result, a three-dimensional metal wiring 440 partially connected to the metal wiring 240 in the recess 420 can be formed on the substrate 210 . The wettability control layer 410 also functions as an interlayer insulating layer between the metal wirings 240 and 440 . Also in this case, if the wettability control layer 220 has the thickness of a self-supporting film, the wettability control layer 220 may be peeled off from the substrate 210 .

Note that steps S310 to S340 may be repeated until a desired three-dimensional structure is obtained.

As described above, since the wettability control layer 220 is made of a polymer material having hydrophobicity and lipophilicity, the wettability control layer 410 can be further formed on the wettability control layer 220. It is also easy to make it three-dimensional. Since the further wettability control layer 410 has not only hydrophobicity but also lipophilicity, various layers can be formed thereon by a coating method using an organic solvent. By adopting the metal wiring forming method of the present invention, flexible multilayer wiring boards, semiconductor packages, and organic transistors can be provided at low cost.

The invention will now be described in detail using specific examples, but it should be noted that the invention is not limited to these examples.

[Examples 1 to 8]
In Examples 1 to 8, various polymer materials and various photomasks were used to form two-dimensional metal wiring.

The raw materials used in Examples 1 to 8 are summarized in Table 1. As polymer materials, cycloolefin (manufactured by Nippon Zeon, Zeonex), polylactic acid (manufactured by Sigma-Aldrich, model number 767344), Cytop (registered trademark) (manufactured by AGC, CTL-809M, CT-SOLV180 as a dilution solvent) were used. . As solvents, xylene (manufactured by Wako Pure Chemical Industries), 1,1,1,3,3,3-hexafluoro-2-propanol (manufactured by Sigma-Aldrich, model number 105228), and ethanol (manufactured by Wako Pure Chemical Industries) were used. These were prepared so as to satisfy the concentration shown in Table 1 to obtain a polymer solution for a wettability control layer. CYTOP has a different structure from both cycloolefin polymers and polylactic acid.

An ink containing metal nanoparticles was synthesized with reference to Non-Patent Document 2. Specifically, silver (Ag) particles with a diameter of 20 nm to 40 nm were modified with phthalocyanine as ligands. It was prepared using water and, if necessary, ethanol so that the concentrations shown in Table 1 were obtained. Polyethylene naphthalate (PEN, manufactured by DuPont Teijin Ltd., thickness 125 μm) was used for the substrate.

A wettability control layer was formed on a PEN substrate by spin coating using the polymer solutions of Examples 1 to 8 (step S110 in FIG. 1). Specifically, a spin coater (manufactured by Mikasa, MS100) was used to form the wettability control layer at a rotational speed of 2000 to 3000 rpm. Then, it was placed on a hot plate and dried under the conditions shown in Table 2 to remove the solvent. The thickness of the wettability control layer thus obtained was measured with a fine shape measuring machine (manufactured by Kosaka Laboratory, Model No. ET200). Further, it was confirmed by measuring the contact angle when anisole, which is a typical organic solvent, was dropped that the resulting wettability control layer satisfies both hydrophobicity and lipophilicity. Table 2 shows the results.

According to Table 2, it was found that CYTOP (registered trademark), which is a fluorine-based resin, does not satisfy the conditions of hydrophobicity and lipophilicity referred to in this specification.

Next, as shown in Table 3, a photomask having a line width of 10 μm or 5 μm is placed on the wettability control layer obtained in Examples 1 to 3 and Examples 5 to 8, and vacuum ultraviolet rays having a wavelength of 200 nm or less are applied. Irradiated (step S120 in FIG. 1). The photomask having a line width of 10 μm further had rectangular electrode pad-shaped openings of 20 μm at intervals of 100 μm in the openings of the line width of 10 μm. A xenon excimer lamp (Ushio Inc., UEM20-172) emitting a wavelength of 172 nm was used for the vacuum ultraviolet rays. Table 3 shows the irradiation conditions. The wettability control layer obtained in Example 4 was irradiated with a KrF excimer laser emitting a wavelength of 248 nm.

Subsequently, as shown in Table 3, a metal ink was applied onto the wettability control layers of Examples 1 to 8 irradiated with the vacuum ultraviolet rays (step S130 in FIG. 1). Metallic ink was applied by a slit coating method. Using a slit coater (TC-3, manufactured by Mitsui Denki Seiki Co., Ltd.), the coating was performed at a coating speed of 5 mm/s.

The state of the metal wiring obtained in Examples 1 to 8 was observed using an optical microscope (manufactured by Nikon). Observation results are shown in FIGS.

5 is an optical microscope image showing the metal wiring of Example 1. FIG.
6 is an optical microscope image showing the metal wiring of Example 2. FIG.

In FIGS. 5 and 6, lines shown bright in grayscale indicate metal wiring. 5 and 6 show that the metal wirings of Examples 1 and 2 both have the line width of the photomask (10 μm). Note that the plurality of rectangular regions exceeding the line width of the metal wiring in the figure are electrode pads corresponding to the portions that connect the upper layer and the metal wiring when three-dimensionalized in Examples 8 and 9 to be described later. be.

Although not shown, the metal wiring of Examples 5 and 6 similarly had the line width of the photomask. From this, it is shown that the thickness of the wettability control layer does not greatly affect the effect of the present invention, and that it is sufficient if the thickness is 10 nm or more and 1000 μm or less, preferably 100 nm or more and 10 μm or less so that the wettability control layer can be applied. rice field. Furthermore, in Example 6, when the wettability control layer was peeled off from the PEN substrate, it was found to function as a film-like two-dimensional metal wiring.

Also, the metal wiring of Example 7 also had the line width of the photomask, but compared to Examples 1 and 2, the boundary between the metal wiring and other portions was not clear in some places. From this, it was shown that the solvent of the metal ink preferably contains 80% by volume or more of water.

Also, the metal wiring of Example 8 similarly had the line width of the photomask (5 μm). From this, it was confirmed that by using the method of the present invention, fine metal wires having a line width of 10 μm or less, or even less than 10 μm, can be easily formed.

On the other hand, the line width of the metal wiring (not shown) of Example 3 did not reach 10 μm. This indicates that the fluoropolymer does not function well as a wettability control layer. The line width of the metal wiring (not shown) of Example 4 exceeded 10 μm. This indicates that vacuum ultraviolet rays having a wavelength of 200 nm or less are preferable for controlling the wettability of the wettability control layer made of a polymeric material used in the present invention.

Examples 1 to 8 above demonstrate that the method of the present invention can easily form a metal wiring having a line width of 10 μm or less.

[Examples 9 to 10]
In Examples 9 and 10, the two-dimensional metal wirings obtained in Examples 1 and 2 were used to form three-dimensional metal wirings. A polymer solution was applied on the metal wiring obtained in Examples 1 and 2 (that is, both the wettability control layer and the metal wiring) under the conditions shown in Tables 1 and 2 to form a further wettability control layer. (Step S310 in FIG. 3). Next, recesses were formed in the electrode pads shown in FIGS. 5 and 6 to expose the metal wiring (step S320 in FIG. 3). The recesses were formed by irradiating an ultraviolet YAG laser with a wavelength of 266 nm (manufactured by V Technology, model number VL-C30).

Next, a photomask having a line width of 10 μm and electrode pad-shaped openings was placed on the further wettability control layer, and vacuum ultraviolet rays of 200 nm or less were irradiated under the conditions shown in Table 3 (step S330 in FIG. 3). Then, as shown in Table 3, a metal ink was applied to the additional wettability control layers and recesses of Examples 9 and 10 irradiated with vacuum ultraviolet rays (step S340 in FIG. 3). This process (steps S310-S340 in FIG. 3) was repeated four times.

When the cross sections of the metal wirings of Examples 9 and 10 thus obtained were observed with an optical microscope, three-dimensional metal wirings in which the metal wirings were bonded by the electrode pads of FIGS. 5 and 6 were obtained. I found out.

When the conductivity was measured between the first and fourth layers of the metal wirings of Examples 9 and 10 obtained in this manner, good conduction was confirmed, and the metal wirings of the electrode pads in FIGS. It was found that a three-dimensional metal wiring in which the wiring was electrically connected was obtained.

A solution of TIPS-pentacene, which is an organic semiconductor, was applied to the metal wiring of Example 3 by a coating method using anisole as an organic solvent, but the organic semiconductor solution was not uniformly applied and an organic semiconductor layer could not be formed. rice field. On the other hand, when the organic semiconductor was applied to the metal wirings of Examples 1 and 2 in the same manner, a uniform organic semiconductor layer could be formed. This indicates that a hydrophobic and lipophilic wettability control layer is important for forming an element such as an organic transistor.

Examples 9 and 10 above show that the method of the present invention can easily form metal wiring having a line width of 10 μm or less, and three-dimensional metal wiring.

[Example 11]
In Example 11, polysilazane was used as the polymer material, a wettability control layer was formed on the substrate, and its properties were evaluated.

As polysilazane, perhydropolysilazane (PHPS; manufactured by AZ Electronic Materials, NA120-20-NAX) was used. Butyl ether (di-n-butyl ether) was used as a solvent, and the concentration of PHPS was adjusted to 20 wt % to obtain a polymer solution for the wettability control layer. Using this polymer solution, a wettability control layer was formed on the same PEN substrate (manufactured by Teijin DuPont Ltd., thickness 125 μm, size 4×4 cm) as in Examples 1 to 8 by spin coating (FIG. 1). step S110). Specifically, a spin coater (MS100 manufactured by Mikasa) was used to apply for 40 seconds at a rotation speed of 5000 rpm to form a wettability control layer. After that, it was placed on a hot plate and dried at 90° C. for 5 minutes, and after removing the solvent, it was dried in a humidity controllable oven at 90° C. and 90% RH for 5 hours.

The wettability control layer after applying the polymer solution to the PEN substrate and the wettability control layer after drying were analyzed using a Fourier transform infrared spectrophotometer (Nicolet 4700DR manufactured by ThermoFisher Scientific). The results are shown in FIG.

7 is an FTIR spectrum of the wettability control layer of Example 11. FIG. In FIG. 7, (1) is the spectrum of the wettability control layer after applying the polymer solution to the PEN substrate, and (2) is the spectrum of the wettability control layer after drying.

In the spectrum of (1), characteristic peaks are seen at 3360 cm ^-1 , 2160 cm ^-1 and 840 cm ^-1 , which are peaks due to stretching vibration of N—H, Si—H and Si—N bonds, respectively. was identified as
On the other hand, in the spectrum of (2), main characteristic peaks are obtained at 1060 cm ⁻¹ and 3500 cm ⁻¹ , which are identified as peaks derived from stretching vibration of Si—O and Si—OH bonds. rice field.
From these results, during the drying process in the oven described above, water molecules act as a catalyst, and the Si—N and Si—H groups of PHPS react to cross-link PHPS, forming a SiO ₂ film. It was suggested that it was converted to

The thickness of the SiO ₂ film thus obtained was measured with a fine shape measuring instrument (manufactured by Kosaka Laboratory Ltd., Model No. ET200) and found to be 0.4 μm (400 nm). The contact angle θ was 0° when anisole was dropped on the obtained SiO ₂ film, and the contact angle θ was 90° when water was dropped.

Next, an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer (V-570 manufactured by JASCO) was used to measure the light transmittance of the resulting SiO ₂ film. The results are shown in FIG.

8 is a spectrum showing the measurement results of the light transmittance of the wettability control layer (SiO ₂ film) of Example 11. FIG.

According to FIG. 8, the _SiO2 film obtained in Example 11 has a very high transparency, comparable to glass, and could well be used as a material for making transparent devices. Do you get it.

In addition, an atomic force microscope (AFM) (SPA400, Seiko Instruments) was used to analyze the surface morphology of the _SiO2 films. The results are shown in FIG.

9 is an AFM image of the wettability control layer (SiO ₂ film) of Example 11. FIG.

As a result of calculating the root mean square roughness (RMS) from the AFM image shown in FIG. 9, a value of 0.21 nm was obtained, confirming that the SiO ₂ film has an extremely smooth surface texture.

Furthermore, a transmission electron microscope (TEM) (JEM2100F from JEOL) was used to analyze the microstructure of the _SiO2 films. A sample for TEM analysis was prepared according to the same procedure as described above, except that a Si wafer was used as the substrate. The results are shown in FIGS. 10(a) and 10(b).

FIG. 10(a) is a TEM image of the wettability control layer (SiO ₂ film) formed on the Si wafer. FIG. 10(b) shows SAED patterns obtained for two regions in the same field of view as in FIG. 10(a).

In the TEM image of FIG. 10(a), the left side of the line extending from the upper left to the lower right is the SiO ₂ film, and the right side is the Si wafer. According to FIG. 10(a), it was found that the SiO ₂ film formed on the Si wafer was a dense film in which Si and O atoms were densely aligned.
In addition, as a result of analyzing the crystal structure by selected area electron diffraction (SAED) for the two regions enclosed by dotted lines in FIG. As shown in 10(b), a pattern indicating an amorphous phase was obtained in the region 1 ( _SiO2 film), whereas the Si atoms were uniformly arranged in the region 2 (Si wafer). A pattern indicating that

Conventionally, in the method of fabricating a SiO ₂ film using PHPS as a precursor, heat treatment was performed under high temperature conditions exceeding 150°C. On the other hand, the wettability control layer (SiO ₂ film) obtained in Example 11 was dried under temperature conditions lower than those of the conventional method in both cases of using PEN and Si wafers as substrates. Therefore, according to the method of the present invention, it is possible to easily form a wettability control layer even on a substrate made of plastic or the like, which is likely to be thermally deformed under high temperature conditions. In addition, there is an advantage in terms of cost.

[Examples 12 to 15]
In Examples 12 to 15, polysilazane was used as the polymer material, and wettability control layers were formed on various substrates by spin coating in the same procedure as in Example 11.

As shown in Table 5, the substrates used in Examples 12-15 were glass, cellulose nanopaper, Si wafer, and PEN, respectively. The glass and Si wafers were ultrasonically cleaned in acetone, isopropanol, and distilled water for 5 minutes each in that order before applying the polymer solution by spin coating. Table 5 shows the materials and sizes of the substrates used in Examples 11 to 15.

For the wettability control layer ( _SiO2 film) formed on each substrate, the surface morphology of the _SiO2 film was analyzed using an atomic force microscope (AFM) (SPA400 manufactured by Seiko Instruments). Table 5 shows the results.

In Example 12, it was confirmed that the wettability control layer (SiO ₂ film) formed on a smooth glass substrate had a root-mean-square roughness (RMS) of 0.21 nm.
In Example 13, the wettability control layer ( _SiO2 film) was successfully formed on the cellulose nanopaper with a rough surface, and the resulting _SiO2 film had a root-mean-square roughness (RMS) of 3.2 nm. It was confirmed that
In Examples 14 and 15, even when using a larger size (large area) Si wafer and a PEN substrate, _respectively , a SiO film can be easily fabricated by the spin coating method, and the obtained SiO The root-mean-square roughness (RMS) of the _two films was determined to be 0.23 nm and 0.21 nm, respectively.

Thus, according to the method of the present invention, it is possible to form a wettability control layer using a wide variety of materials as substrates, regardless of whether they are organic materials or inorganic materials. It is possible.

[Example 16]
In Example 16, polysilazane is used as the polymer material, and the step of forming a wettability control layer by spin coating is repeated three times in the same procedure as in Example 11, thereby forming a wettability control layer with a three-layer structure on the PEN substrate. did.

FIG. 11 is a schematic diagram showing the step of forming a three-layer wettability control layer (SiO ₂ film) (right side) of Example 16 on a PEN substrate (left side). In each formation step, the rotation speed of the spin coater was set to 3000 rpm (first layer), 2000 rpm (second layer), and 4000 rpm (third layer), and the wettability control layer was coated for 40 seconds each. The thickness of the

The thickness of each layer of the obtained wettability control layer (SiO ₂ film) having a three-layer structure was measured using a scanning white light interference microscope (VS1530 manufactured by Hitachi High-Tech). The results are shown in FIG.

FIG. 12 is a diagram showing the analysis results of the wettability control layer (SiO ₂ film) of Example 16 with a scanning white light interference microscope.

According to FIG. 12, the three wettability control layers ( _SiO2 films) formed on the PEN substrate are 500 nm (first layer), 706 nm (second layer), and 460 nm (third layer), respectively. )Met. This result indicates that the thickness of the wettability control layer formed on the substrate can be controlled by the method of the present invention.

More specifically, when the spin coating method is used to apply the polymer solution to the substrate, the wettability formed on the substrate can be controlled by changing the rotation speed of the spin coater, that is, the speed of spin coating. It was experimentally proven that the thickness of the control layer ( _SiO2 film) can be controlled on the order of nanometers. In addition, this is consistent with the theoretical relational expression expressed using the concentration of the polymer material in the polymer solution and the rotation speed of the spin coater, and the results of the preliminary experiments separately conducted by the present inventors. match.
In addition, compared with the conventional methods of forming _SiO2 films by chemical vapor deposition and sputtering, the method of the present invention enables the formation of various materials such as glass, silicon, nanopaper, and polymers under lower temperature conditions. Using the material as a substrate, an extremely smooth SiO ₂ film can be easily formed, thereby modifying the surface of the substrate material. In particular, the ability to form a multi-layered wettability control layer ( _SiO2 film) in a layer-by-layer fashion by a solution process is advantageous in forming three-dimensional metal wiring. .

[Example 17]
In Example 17, the wettability control layer (SiO ₂ film) obtained in Example 11 was used to form a two-dimensional metal wiring.

Specifically, a photomask having a line width of 10 μm was placed on the wettability control layer (SiO ₂ film) obtained in Example 11, and vacuum ultraviolet rays having a wavelength of 200 nm or less were irradiated (step S120 in FIG. 1). A photomask having a line width of 10 μm has a structure in which an opening with a line width of 10 μm extends in one direction, bends 180° at an end portion to extend in the opposite direction, and bends at an opposite end portion by 180° to extend. It was repeated and the openings had a continuous structure (pattern) as a whole. A xenon excimer lamp (Ushio, UEM20-172) emitting a wavelength of 172 nm was used for the vacuum ultraviolet rays, and the irradiation time was 80 seconds.

Subsequently, a metal ink was applied onto the SiO ₂ film irradiated with the vacuum ultraviolet rays (step S130 in FIG. 1). Inks containing metal nanoparticles were synthesized with reference to Non-Patent Documents 2 and 3. Specifically, gold (Au) particles with a diameter of about 30 nm were prepared with water to a concentration of 25 wt%. Metallic ink was applied by a slit coating method. Using a slit coater (TC-3, manufactured by Mitsui Denki Seiki Co., Ltd.), the coating was performed at a coating speed of 5 mm/s.

The appearance of the obtained metal wiring was observed using an optical microscope (manufactured by Nikon). Observation results are shown in FIG.

13 is an optical microscope image showing the metal wiring of Example 17. FIG.

In FIG. 13, lines (patterns) shown brightly in gray scale indicate metal wiring. According to FIG. 13, it was found that the metal wiring of Example 17 had the line width (10 μm) of the photomask, and a wiring pattern reflecting the structure of the opening of the photomask with high accuracy was obtained. rice field.

[Example 18]
In Example 18, the wettability control layer (SiO ₂ film) obtained in Example 11 was used to form a three-dimensional metal wiring.

Specifically, the photomask having a line width of 10 μm was the same as in Example 17, except that a photomask having a line width of 10 μm and a rectangular electrode pad-shaped opening of 20 μm at intervals of 100 μm was used. A two-dimensional metal wiring was formed on the wettability control layer (SiO ₂ film) according to the procedure.
Next, on the obtained metal wiring (that is, _both the wettability control layer (SiO film) and the metal wiring), a polymer solution is applied under the same conditions as in Example 11, and a further wettability control layer (SiO ₂ film) was formed (step S310 in FIG. 3). Next, recesses were formed in the electrode pads to expose the metal wiring (step S320 in FIG. 3). The recesses were formed by irradiating an ultraviolet YAG laser with a wavelength of 266 nm (manufactured by V Technology, model number VL-C30).

Next, a photomask having a line width of 10 μm and electrode pad-shaped openings was placed on the further wettability control layer (SiO ₂ film) and irradiated with vacuum ultraviolet rays of 200 nm or less under the same conditions as in Example 17 (Fig. 3 step S330). At this time, the photomask was arranged with the orientation changed by 90° from that when forming the first-layer metal wiring. Next, under the same conditions as in Example 17, a metal ink was applied to the additional wettability control layer (SiO ₂ film) and recesses irradiated with vacuum ultraviolet rays (step S340 in FIG. 3). Thus, a three-dimensional metal wiring having a two-layer structure was formed.

The appearance of the obtained metal wiring was observed using an optical microscope (manufactured by Nikon). The observation results are shown in FIGS. 14(a) to 14(c).

FIG. 14(a) is an optical microscope image showing the metal wiring of Example 18. FIG. FIG. 14(b) is an enlarged image of the portion surrounded by the dotted line in FIG. 14(a). FIG. 14(c) is a schematic diagram showing the structure of the portion shown in FIG. 14(b).

In FIG. 14(a), the bright gray-scale lines indicate the metal wiring. According to FIG. 14(a), it was found that the metal wiring of Example 18 had the line width (10 μm) of the photomask. 14(a), one of a plurality of rectangular regions exceeding the line width of the metal wiring was enlarged, and an electrode pad was obtained as shown in FIG. 14(b). It was found that a three-dimensional metal wiring in which the metal wiring was bonded was obtained. FIG. 14(c) schematically shows this state.

Further, when the conductivity between the first layer and the second layer of the metal wiring of Example 18 obtained in this manner was measured, good conduction was confirmed, and the electrode pad of FIG. It was found that a three-dimensional metal wiring in which the was electrically coupled was obtained.

By using the method of forming the thin metal wire of the present invention, an effective vacuum device or the like is not required, so that semiconductor devices and electronic circuits can be provided at low cost.

210 substrate 220 wettability control layer 230, 430 portion having hydrophilicity 240, 440 metal wiring 410 further wettability control layer 420 concave portion

Claims (20)

A polymer solution containing at least one polymer material selected from the group consisting of a cycloolefin polymer, polylactic acid, derivatives thereof, and polysilazane in the step of forming a wettability control layer on a substrate. onto the substrate and dried to form a hydrophobic and lipophilic wettability control layer ;
a step of irradiating the wettability control layer with vacuum ultraviolet rays having a wavelength of 200 nm or less;
and applying a metal ink on the wettability control layer. The method according to claim 1, wherein the metal ink is a composition in which metal nanoparticles are dispersed in a dispersion medium. The metal nanoparticles are gold (Au), silver (Ag), copper (Cu), platinum (Pt), iron (Fe), nickel (Ni), tin (Sn), zinc (Zn), lead (Pb) , palladium (Pd), aluminum (Al), and a metal selected from the group consisting of alloys thereof;
3. The method of claim 2, wherein the dispersion medium contains at least water. 4. The method according to claim 3, wherein the water content in the dispersion medium is 80% by volume or more. The method according to any one of claims 1 to 4, wherein the vacuum ultraviolet rays have a wavelength in the range of 150 nm or more and 200 nm or less. 6. The method according to any one of claims 1 to 5, wherein said vacuum ultraviolet rays have irradiation energy in the range of 1 mW/cm ² to 100 mW/cm ² . The method according to any one of claims 1 to 6, wherein the step of irradiating the vacuum ultraviolet rays irradiates the vacuum ultraviolet rays for 5 seconds or more and 1000 seconds or less. The method according to any one of claims 1 to 7, wherein the step of irradiating with vacuum ultraviolet rays uses a photomask or a metal mask. The method according to any one of claims 2 to 4, wherein the concentration of said metal nanoparticles in said metal ink is in the range of 1 wt% to 60 wt%. In the step of applying the metal ink, the application is performed by a spin coating method, a spray coating method, a dip coating method, a slit coating method, a slot coating method, a bar coating method, a roll coating method, a curtain coating method, an inkjet method, and, The method according to any one of claims 1 to 9, which is performed by a method selected from the group consisting of screen printing methods. 11. The method according to any one of claims 1 to 10, wherein the step of applying the metal ink includes applying the metal ink on the wettability control layer and drying it. In the step of forming the wettability control layer, the coating is performed by a spin coating method, a spray coating method, a dip coating method, a slit coating method, a slot coating method, a bar coating method, a roll coating method, a curtain coating method, an inkjet method, and screen-printing methods. 13. The wettability control layer according to any one of claims 1 to 12, wherein in the step of forming the wettability control layer, the drying is performed by heating the applied polymer solution in a temperature range of 30°C or higher and 200°C or lower. the method of. The method according to any one of claims 1 to 13, wherein the concentration of polymeric material in the polymeric solution ranges from 0.1 wt% to 50 wt%. 15. The method of claim 14, wherein the concentration of polymeric material in the polymeric solution ranges from 0.5 wt% to 30 wt%. Solvents for the polymer solution include xylene, hexafluoro-2-propanol, benzene, toluene, mesitylene, cyclohexane, dichloromethane, chloroform, carbon tetrachloride, propylene glycol monomethyl ether acetate, methyl ether, ethyl ether, propyl ether, and The method according to any one of claims 1 to 15, wherein at least one is selected from the group consisting of butyl ether. Following the step of applying the metallic ink,
In the step of forming a further wettability control layer, a polymer solution containing at least one polymer material selected from the group consisting of a cycloolefin polymer, polylactic acid, derivatives thereof, and polysilazane, applying on the wettability control layer and the metal wiring obtained by applying the metal ink, drying , and forming a further wettability control layer having hydrophobicity and lipophilicity ;
forming a recess in the further wettability control layer to expose at least a portion of the metal wiring;
a step of irradiating the further wettability control layer with vacuum ultraviolet rays having a wavelength of 200 nm or less;
and applying a metallic ink on said further wettability control layer and said recesses. 18. The method of claim 17, wherein the exposing step irradiates with an ultraviolet laser. 19. The method of claim 17 or 18, further comprising repeating the steps of forming a further wettability control layer, exposing, irradiating and applying. The method of any of claims 1-19, further comprising peeling the wettability control layer from the substrate.

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