Method for forming metal pattern

Abstract

The present invention provides a method for forming a metal pattern, comprising: a step of preparing a first substrate having a pattern of a lyophilic portion having lyophilicity to a liquid containing a metal component and a lyophobic portion having lyophobicity to the liquid containing a metal component; a step of preparing a second substrate for holding the liquid containing a metal component; and a step of bringing the first substrate and the second substrate into contact and transferring the liquid containing a metal component from the second substrate to the lyophilic portion of the first substrate. The method for forming a metal pattern can form a high-precision metal pattern that prevents metal from being attached to unnecessary positions of the substrate.

Description

Technical Field

[0001] The present invention relates to a method for forming a metal pattern for forming a metal pattern serving as wiring or the like on a surface of a substrate. Background Art

[0002] There is known a technique for forming a desired wiring structure using conductive ink (conductive ink) containing a conductive material such as metal.

[0003] As a common method, there is known a method in which a conductive ink is applied to an arbitrary substrate, the conductive ink is cured using a mask having an opening pattern corresponding to the wiring to be formed, and excess conductive ink is washed away except for the lyophilic portion.

[0004] On the other hand, as a method capable of forming a fine metal pattern, a method of forming a metal pattern using a nanoimprint technique is known.

[0005] In the formation of a metal pattern using nanoimprint technology, as described in Patent Document 1, first, a fine groove corresponding to the metal pattern is formed on a base material (substrate) on which a metal pattern (conductive pattern) is formed. Next, a conductive ink is applied to the base material on which the groove is formed. Thereafter, the conductive ink is dried, and after being cured by heat treatment and sintering as needed, the conductive ink except for the groove is removed, thereby forming a metal pattern on the base material.

[0006] By using nanoimprint technology, fine metal patterns can be formed.

[0007] On the other hand, in the formation of a metal pattern using the nanoimprint technique, there is a problem that as the fineness of the metal pattern increases, it becomes more difficult to accurately form a groove.

[0008] On the other hand, there is also known a method for forming a metal pattern by utilizing the lyophilicity and lyophobicity to a conductive ink without providing projections and depressions on a substrate.

[0009] In this method, the lyophilic part and the lyophobic part of the conductive ink are patterned on the surface of the substrate according to the formed metal pattern to provide the lyophilic part and the lyophobic part of the conductive ink. The conductive ink is applied to the substrate having the pattern of the lyophilic part and the lyophobic part, and selectively adheres to the lyophilic part, thereby forming the metal pattern.

[0010] For example, Patent Document 2 describes a method for forming a metal pattern using the lyophilicity and lyophobicity of a fluorinated vinyl resin.

[0011] In the method described in Patent Document 2, first, a fluorine-containing resin layer is formed on the surface of a substrate, and then a functional group is formed in a metal pattern forming portion (pattern forming portion) of the fluorine-containing resin layer. Next, a conductive ink (metal particle dispersion) in which metal particles protected by an amine compound as a first protective material and a fatty acid as a second protective material are dispersed in a solvent is applied, for example, by a doctor blade method.

[0012] In this method, the conductive ink is bounced by the liquid-repellent based on the fluorine-containing resin without functional groups at the position other than the pattern forming part. And, in the case of using a scraper method, the bounced conductive ink can be removed from the surface of the substrate. On the other hand, in the pattern forming part, the metal particles can be bonded to the functional groups of the pattern forming part and fixed. According to the method described in Patent Document 2, the desired metal pattern can be formed on the substrate.

[0013] Previous technical literature

[0014] Patent Literature

[0015] Patent Document 1: Japanese Patent Application Publication No. 2016-139688

[0016] Patent Document 2: Japanese Patent Application Publication No. 2016-048601 Summary of the invention

[0017] Technical issues to be solved by the invention

[0018] In the method using nanoimprinting as described in Patent Document 1, or in the method using a pattern of a lyophilic portion and a lyophobic portion for a conductive ink as described in Patent Document 2, a fine metal pattern can also be formed.

[0019] Here, it is preferred that the substrate on which the metal pattern is formed has no conductive ink, that is, no conductive material such as metal attached except for the portion where the metal pattern is formed.

[0020] However, in these conventional methods for forming a metal pattern, it is not possible to sufficiently prevent the conductive ink from adhering to areas other than the area where the metal pattern is formed.

[0021] The purpose of the present invention is to solve the problems of the prior art and to provide a method for forming a metal pattern. When forming a metal pattern on a substrate, the metal is not attached to unnecessary positions of the substrate and metal is selectively supplied at the position where the metal pattern is formed, thereby forming a high-precision metal pattern.

[0022] Means for solving technical problems

[0023] In order to solve the problem, the present invention has the following structure.

[0024] [1] A method for forming a metal pattern, which is a method for forming a metal pattern on a substrate using a liquid containing a metal component, the method for forming a metal pattern comprising:

[0025] a step of preparing a first substrate, the first substrate having a lyophilic portion having lyophilicity to a liquid containing a metal component and corresponding to a metal pattern to be formed and a lyophobic portion having lyophobicity to the liquid containing a metal component;

[0026] a step of preparing a second substrate, wherein the second substrate holds a liquid containing a metal component; and

[0027] A step of bringing a first substrate into contact with a second substrate and transferring a metal component-containing liquid from the second substrate to the lyophilic portion of the first substrate.

[0028] [2] The method for forming a metal pattern according to [1], wherein:

[0029] The second substrate is in the form of a roll.

[0030] [3] The method for forming a metal pattern according to [1] or [2], wherein:

[0031] The second substrate holds the metal component-containing liquid in a dotted form.

[0032] [4] The method for forming a metal pattern according to any one of [1] to [3], wherein:

[0033] The contact angle between the metal component-containing liquid and the lyophilic portion of the first substrate is 15° or less.

[0034] The contact angle between the metal component-containing liquid and the lyophobic portion of the first substrate is 70° or more.

[0035] [5] The method for forming a metal pattern according to any one of [1] to [4], wherein:

[0036] The difference between the contact angles of the metal component-containing liquid with the lyophilic portion and the lyophobic portion of the first substrate is 70° or more.

[0037] [6] The method for forming a metal pattern according to any one of [1] to [5], wherein:

[0038] The surface tension of the metal component-containing liquid at 25° C. is 22 to 35 dyn / cm.

[0039] [7] The method for forming a metal pattern according to any one of [1] to [6], wherein:

[0040] The first substrate is set at a higher temperature than the second substrate, and the first substrate is brought into contact with the second substrate.

[0041] [8] The method for forming a metal pattern according to any one of [1] to [7], wherein:

[0042] The metal component-containing liquid is an aqueous solution of metal particles or a metal compound, or a dispersion in which metal particles or a metal compound are dispersed in water.

[0043] [9] The method for forming a metal pattern according to any one of [1] to [8], wherein:

[0044] The second substrate holds the metal component-containing liquid in accordance with the metal pattern to be formed on the first substrate.

[0045]

[10] The method for forming a metal pattern according to any one of [1] to [9], wherein:

[0046] Before the first substrate and the second substrate come into contact with each other, the metal component-containing liquid held by the second substrate is adjusted.

[0047]

[11] The method for forming a metal pattern according to

[10] , wherein:

[0048] The adjustment of the metal component-containing liquid is one or more of adjustment of viscosity, adjustment of surface tension, and adjustment of concentration.

[0049] Effects of the Invention

[0050] According to the present invention, metal is prevented from being attached to unnecessary positions and metal is selectively supplied to positions where a metal pattern is to be formed, thereby making it possible to form a metal pattern with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a conceptual diagram for explaining the preparation of the first substrate in the method for forming a metal pattern of the present invention.

[0052] Figure 2 This is a conceptual diagram for explaining the preparation of the second substrate in the method for forming a metal pattern of the present invention.

[0053] Figure 3 This is a conceptual diagram for explaining transfer in the method for forming a metal pattern of the present invention.

[0054] Figure 4 This is a conceptual diagram showing one example of a different example of the method for forming a metal pattern of the present invention. DETAILED DESCRIPTION

[0055] Hereinafter, the coating method of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0056] In addition, in the present invention, a numerical range expressed by "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0057] The method for forming a metal pattern of the present invention forms a metal pattern on the surface of a substrate having a lyophilic portion and a lyophobic portion patterned according to the formed metal pattern by utilizing lyophilicity and lyophobicity to a liquid containing a metal component.

[0058] Here, in the conventional method for forming a metal pattern using lyophilicity and lyophobicity as described in Patent Document 2, a conductive ink is directly applied to a substrate having a lyophilic portion and a lyophobic portion corresponding to the metal pattern to be formed.

[0059] In contrast, in the method for forming a metal pattern of the present invention, the metal pattern is formed on the substrate by transferring the metal component-containing liquid from another substrate instead of coating on the substrate having the lyophilic portion and the lyophobic portion corresponding to the metal pattern. Specifically, in the present invention, the metal component-containing liquid is transferred from the second substrate holding the metal component-containing liquid to the first substrate having the pattern of the lyophilic portion and the lyophobic portion formed thereon, thereby forming the metal pattern on the first substrate.

[0060] In the following description, for convenience, the metal component-containing liquid for forming a metal pattern is also referred to as "conductive ink".

[0061] Furthermore, for convenience, the pattern of the lyophilic portion having lyophilicity to the conductive ink and the lyophobic portion having lyophilicity to the conductive ink corresponding to the formed metal pattern is also referred to as a “lyophilic-phobic pattern”.

[0062] In the following description, unless otherwise specified, the lyophilicity, lyophobicity, and lyophilicity pattern refer to the lyophilicity, lyophobicity, and lyophilicity pattern with respect to the conductive ink.

[0063] Figure 1 An example of a method for forming a first substrate having a proximity pattern is conceptually shown in FIG.

[0064] First, if Figure 1 As shown on the left side of FIG. 1 , a support 12 serving as a first substrate to form a metal pattern is prepared.

[0065] The support 12 is not limited, and by forming a metal pattern, various articles used as a support (base material, substrate) can be used in various devices, parts, and components used in wiring substrates, integrated circuits, semiconductor devices, electronic devices, and the like.

[0066] As the support body 12, as an example, there can be illustrated sheet-like objects (plate-like objects, films) such as resin films made of resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cycloolefin polymer (COP), polyimide, cycloolefin copolymer (COC) and triacetyl cellulose (TAC), glass plates and silicon wafers.

[0067] Furthermore, the support 12 may have an arbitrary film (layer) formed on the surface of these sheet-like objects.

[0068] The film formed on the surface of the sheet is not limited and may be an organic material or an inorganic material. Examples of the film formed on the surface of the sheet include a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and an aluminum oxide film.

[0069] These membranes can be either lyophilic or lyophobic.

[0070] The method for forming these films is not limited, and they may be formed (film-formed) by a known method such as sputtering and a vapor deposition method such as plasma CVD (Chemical Vapor Deposition), a coating method, and affixing a sheet according to the film to be formed.

[0071] The thickness of the sheet-shaped support 12 is not limited. That is, the thickness of the support 12 may be appropriately set according to the application of the first substrate to be metal-patterned by the method of the present invention.

[0072] Furthermore, the sheet-like support 12 may be a flexible support or an inflexible support. In consideration of the ease of transfer, etc., the sheet-like support 12 is preferably flexible in the present invention.

[0073] In the method for forming a metal pattern of the present invention, the first substrate for forming a metal pattern is not limited to a sheet-shaped object, and objects of various shapes such as spheres, cubes, cuboids, columns, cones, and irregular shapes can also be used as the substrate.

[0074] Furthermore, the first substrate on which the metal pattern is formed according to the present invention may be a raw material, an intermediate product, or a finished product.

[0075] As from Figure 1 As shown in the second figure from the left, a liquid-repellent film 14 having liquid-repellency to the conductive ink is formed on one main surface of the support 12 .

[0076] The liquid-repellent film 14 is not limited, and a film made of a material having liquid-repellency to the conductive ink can be used depending on the solvent or dispersion medium of the conductive ink.

[0077] For example, when the conductive ink is an aqueous solution or a dispersion using water as a dispersion medium, a film composed of a fluorine-containing compound such as polytetrafluoroethylene (PTFE) can be exemplified as the liquid-repellent film 14. The film composed of the fluorine-containing compound can also preferably utilize a commercial product. As commercial products of the film composed of the fluorine-containing compound, OPTOOL (DAIKIN INDUSTRIES, LTD.,), NOVEC (3M Company), and KBM1903 (Shin-Etsu Chemical Co., Ltd.) can be exemplified.

[0078] Then, as from Figure 1 As shown in the third from the left, the liquid-repellent film 14 is processed through a mask 16 having an opening corresponding to the formed metal pattern, and the processed portion is hydrophilized. In the example shown in the figure, as an example, ultraviolet rays (Ultra Violet) are irradiated from a light source UV through the mask 16, thereby hydrophilizing the ultraviolet irradiated portion of the liquid-repellent film 14.

[0079] Therefore, if Figure 1 As shown on the right side of , according to the formed metal pattern, a first substrate 10 is produced on a support 12 to form an affinity pattern 18, wherein the affinity pattern 18 has a lyophobic portion 18a that is lyophobic to the conductive ink and a lyophilic portion 18b (diagonal line portion) that is lyophilic to the conductive ink.

[0080] The lyophilic treatment of the liquid-repellent film 14 is not limited, and various treatments capable of lyophilizing the liquid-repellent film 14 can be used depending on the type of the liquid-repellent film 14 .

[0081] As an example, in addition to the UV irradiation shown in the figure, ozone irradiation, plasma treatment, electron beam irradiation, etc. can be exemplified.

[0082] The method for forming the metal pattern of the present invention is not limited to the method of making the liquid-repellent film 14 lyophilic by these treatments.

[0083] For example, when the support 12 is lyophilic, the lyophobic film 14 can be removed according to the formed metal pattern by UV irradiation, ozone irradiation, plasma treatment, electron beam irradiation, and etching through the mask 16, thereby producing the first substrate 10 having the lyophilic pattern 18.

[0084] When the support 12 is lyophobic, the lyophobic film 14 can be removed according to the formed metal pattern by UV irradiation through the mask 16 and the removed portion of the lyophobic film 14 in the support 12 can be made lyophilic, thereby manufacturing the first substrate 10 having the hydrophilic pattern 18 .

[0085] In addition, when the support body 12 is liquid-repellent, by UV irradiation through a mask 16, etc., the liquid-repellent film 14 is removed according to the formed metal pattern, and then UV irradiation, ozone irradiation and plasma treatment are performed, and the removed portion of the liquid-repellent film 14 of the support body 12 is made lyophilic, so that the first substrate 10 having a lyophilic pattern 18 can be produced.

[0086] In the present invention, the lyophilic treatment for forming the lyophilic pattern on the lyophobic film 14 is not limited to the method using the mask 16 .

[0087] For example, by performing a light beam scanning using a laser beam or the like modulated by a known modulation method such as pulse modulation, intensity modulation, and area modulation, the lyophilic treatment of the liquid-repellent film 14 can be performed as described above.

[0088] In the present invention, there is no limitation on the method for preparing the first substrate having the affinity pattern of the conductive ink. That is, in the method for forming the metal pattern of the present invention, the method for preparing the first substrate can utilize any of the known methods for forming the metal pattern and the conductive pattern by utilizing the affinity pattern.

[0089] For example, in Figure 1 In the method shown, a lyophobic film is formed on the surface of the support 12 and a lyophilic treatment is performed corresponding to the formed metal pattern, thereby forming a hydrophilic pattern on the support 12. However, in the present invention, a lyophilic film having lyophilicity is formed on the surface of the support 12, and a lyophilic treatment is performed on the lyophilic film according to the formed metal pattern, thereby making it possible to produce a first substrate having a hydrophilic pattern formed on the support 12.

[0090] Alternatively, ozone irradiation, plasma treatment, UV irradiation, electron beam irradiation, etc. are performed on the lyophobic support 12 through a mask corresponding to the formed metal pattern, and the support 12 is treated to be lyophilic according to the metal pattern, thereby forming a first substrate having a hydrophilic pattern formed on the support 12. Conversely, various treatments as described above are performed on the lyophilic support 12 through a mask corresponding to the formed metal pattern, and the support 12 is treated to be lyophobic, thereby forming a first substrate having a hydrophilic pattern formed on the support 12.

[0091] Alternatively, a casting mold (transfer member, stamp) having convex portions corresponding to the lyophobic portions of the affinity-dispersion pattern is used, and after a lyophilic film is formed on the support 12, a lyophobic material is applied to the convex portions of the casting mold, and the lyophobic material is transferred to the surface of the lyophilic film, thereby making it possible to produce the first substrate 10 having an affinity-dispersion pattern formed on the support 12. Conversely, a casting mold having convex portions corresponding to the lyophilic portions of the affinity-dispersion pattern is used, and after a lyophilic film is formed on the support 12, a lyophilic material is applied to the convex portions of the casting mold, and the lyophobic material is transferred to the surface of the lyophilic film, thereby making it possible to produce the first substrate 10 having an affinity-dispersion pattern formed on the support 12.

[0092] In the first substrate 10 on which the affinity-repulsion pattern is formed in this manner, the surface on which the affinity-repulsion pattern is formed may be a flat surface, or may have projections and depressions in which the lyophilic portion 18 b is concave.

[0093] In the method for forming a metal pattern of the present invention, there is no limitation on the lyophilicity or wettability of the conductive ink in the first substrate 10. The contact angle of the conductive ink with the lyophobic portion 18a may be larger than the contact angle with the lyophilic portion 18b.

[0094] In the first substrate 10 , the contact angle between the conductive ink and the liquid-repellent portion 18 a is preferably 70° or more.

[0095] The contact angle between the conductive ink and the lyophobic portion 18a is preferably set to 70° or more, because the conductive ink can be prevented from adhering to the lyophobic portion 18a, i.e., the portion where the metal pattern is not formed in the first substrate 10, and the conductive ink can easily flow into the lyophilic portion 18b.

[0096] The contact angle between the conductive ink and the liquid-repellent portion 18 a is more preferably 80° or more, and further preferably 85° or more.

[0097] In the first substrate 10 , the contact angle between the conductive ink and the lyophilic portion 18 b is preferably 15° or less.

[0098] By setting the contact angle between the conductive ink and the lyophilic portion 18b to be 15° or less, the conductive ink can be selectively attached to the lyophilic portion 18b, i.e., the portion where the metal pattern is formed in the first substrate 10, and the conductive ink can be easily applied and spread in the lyophilic portion 18b.

[0099] The contact angle between the conductive ink and the lyophilic portion 18 b is more preferably 13° or less, and further preferably 10° or less.

[0100] The difference between the contact angle between the conductive ink and the lyophobic portion 18a and the contact angle between the conductive ink and the lyophilic portion 18b is preferably large. Specifically, the difference between the contact angle between the conductive ink and the lyophobic portion 18a and the contact angle between the conductive ink and the lyophilic portion 18b is preferably 70° or more.

[0101] By setting the difference in contact angle between the conductive ink and the lyophobic portion 18a and the lyophilic portion 18b to be 70° or more, it is preferable to prevent the conductive ink from adhering to the lyophobic portion 18a and selectively adhere the conductive ink to the lyophilic portion 18b, thereby forming a metal pattern with higher precision.

[0102] The contact angle of the conductive ink on the first substrate 10 is the contact angle of the conductive ink 26 when applied to the second substrate 20 before conditioning of the conductive ink such as heating in the second substrate 20 described later.

[0103] This also applies to the physical properties of the conductive ink such as viscosity and surface tension described later.

[0104] On the other hand, Figure 2 As shown conceptually, a second substrate 20 holding the conductive ink is prepared.

[0105] First, if Figure 2 As shown in the left and center of FIG. , a conductive ink 26 is applied to one surface of a sheet-like support 24 .

[0106] As the support 24 of the second substrate 20 , various sheet-like materials exemplified in the support 12 of the first substrate 10 described above can be used.

[0107] The thickness of the support body 24 is not limited, and may be appropriately set according to the material forming the support body 24 so as to obtain sufficient strength and rigidity.

[0108] The support 24 may or may not be flexible, but is preferably flexible in consideration of the ease of transfer described later.

[0109] In the support 24 of the second substrate 20 , the surface on which the conductive ink 26 is applied may be either liquid-repellent or liquid-philic with respect to the conductive ink 26 , but is preferably liquid-philic.

[0110] Specifically, it is preferred that the contact angle between the conductive ink 26 and the applied surface of the support 24 be lyophilic, that is, about 1 to 60°.

[0111] The contact angle between the conductive ink 26 and the support 24 is preferably 1 to 60 degrees, because the support 24 can accurately hold the conductive ink 26 and excess liquid can be removed from the first substrate 10 after transfer.

[0112] The contact angle between the conductive ink 26 and the support 24 is more preferably 10 to 50°.

[0113] In the second substrate 20, a support 24 formed of a material having lyophilicity to the conductive ink 26 may be used, or a support 24 formed of a material having lyophobicity to the conductive ink 26 may be surface-treated to be lyophilic. The support 24 may be a support formed of a material having lyophilicity to the conductive ink 26 subjected to a lyophilic treatment.

[0114] The method of increasing the lyophilicity of the support 24 is not limited, and various known methods can be used depending on the material forming the support 24 and the solvent or dispersion medium of the conductive ink.

[0115] As an example, methods such as UV irradiation, ozone irradiation, plasma treatment, and electron beam irradiation can be illustrated.

[0116] The conductive ink 26 is also not limited, and various conductive inks used for forming metal patterns (conductive patterns, wiring patterns) and the like on substrates can be used.

[0117] As an example, there can be mentioned a conductive ink in which metal particles are dispersed in a solvent, a conductive ink in which metal particles are dissolved in a solvent, a conductive ink in which a metal compound is dispersed in a solvent, and a conductive ink in which a metal compound is dispersed in a solvent.

[0118] In addition, in the method for forming a metal pattern of the present invention, in addition to the conductive ink using metal particles or metal compounds, conductive inks in which various conductive materials are dispersed or dissolved, such as conductive inks in which conductive polymers are dispersed, can be used.

[0119] The solvent and the dispersion medium are not limited and can be appropriately selected according to the metal particles and the metal compound. The solvent and the dispersion medium are preferably water. That is, the conductive ink 26 is preferably an aqueous solution or a dispersion using water as the dispersion medium.

[0120] The metal particles are not limited, and particles of various conductive metals such as various silver particles, copper particles, gold particles, and titanium particles can be used.

[0121] The particle size of the metal particles is not limited either. The particle size of the metal particles is preferably 0.1 nm to 1 μm, more preferably 3 to 300 nm, and even more preferably 5 to 100 nm.

[0122] The metal compound is also not limited, and various compounds containing the above-mentioned metals can be used. Furthermore, the metal compound may be a complex.

[0123] As the conductive ink 26 , commercially available conductive inks used for forming metal patterns, conductive patterns, and wiring patterns in the manufacture of transparent conductive films for touch panels, wiring for flexible devices, electrodes, solar cells, and RFID (Radio Frequency IDentifier) ​​can be preferably used.

[0124] As an example, conductive inks EI-1104, EI-710, and EI-1201 manufactured by Electroninks, conductive ink SR7000 manufactured by Bando Chemical Industries, Ltd., Future Ink manufactured by Future Ink, and C ink manufactured by C-INK Co., Ltd. can be exemplified.

[0125] The surface tension of the conductive ink 26 is not limited.

[0126] The surface tension of the conductive ink 26 is preferably 22 to 35 dyn / cm at 25° C. Setting the surface tension of the conductive ink to 22 to 35 dyn / cm is preferred in that the shape of dots when the conductive ink 26 is applied in dots as described below can be well-balanced with the coating and diffusion, and the shape of the metal pattern can be improved.

[0127] The surface tension of the conductive ink at 25° C. is more preferably 22 to 32 dyn / cm, and further preferably 23 to 30 dyn / cm.

[0128] There is no limitation on the viscosity of the conductive ink 26. The viscosity of the conductive ink 26 is preferably 1 to 100 cP.

[0129] The viscosity of the conductive ink 26 is preferably set to 1 to 100 cP, because droplets are formed stably when the conductive ink 26 is applied to the support 24, coating properties are stable, and inkjet compliance is stable when the conductive ink 26 is applied to the support 24 by inkjet.

[0130] The viscosity of the conductive ink 26 is more preferably 3 to 30 cP, and further preferably 5 to 25 cP.

[0131] The method of applying the conductive ink 26 to the support 24 is also not limited, and various known application methods can be used.

[0132] Examples include an inkjet coating method, a curtain coating method, a roll coating method, a spray coating method, a bar coating method, a dispensing method, and a die coating method.

[0133] As described below, the conductive ink 26 is preferably applied to the support 24 according to the formed metal pattern. In view of this, the conductive ink 26 can also be preferably applied to the support 24 by printing methods such as inkjet printing, flexographic printing, offset printing, and gravure printing.

[0134] Here, as will be described later, the second substrate 20 preferably holds the conductive ink 26 in the form of dots separated from each other.

[0135] Considering this point, it is preferable to use a spray method as a method for applying the conductive ink 26, because the conductive ink 26 can be applied in a dotted form and the dot size can be easily changed. The spray method can use various known methods such as a single-fluid spray method, a two-fluid spray method, an ultrasonic spray method, an electrostatic capacitance spray method, and a centrifugal spray method.

[0136] Furthermore, the inkjet method is also preferably used as a method for applying the conductive ink 26 in that the conductive ink 26 can be applied to the support 24 in a dotted form.

[0137] In the method for forming a metal pattern of the present invention, the conductive ink 26 held by the second substrate 20 may be a so-called solid film having a uniform surface over the entire surface. Figure 2 As shown in the center, preferably they are dots separated from each other.

[0138] That is, in the present invention, it is preferred to apply the conductive ink 26 to the support 24 of the second substrate 20 by using a method such as a spray method or an inkjet method to scatter droplets for application. By using a spray method or an inkjet method, the conductive ink 26 can be applied to the support 24 of the second substrate 20 in a manner such that the droplets are separated and independent of each other in the form of dots. As a result, the conductive ink 26 in the form of dots can be maintained on the second substrate 20.

[0139] By setting the conductive ink 26 retained by the second substrate 20 in a dot shape, it is preferred that the conductive ink 26 is easily transferred from the second substrate 20 to the first substrate 10, the amount of the conductive ink 26 transferred to the first substrate 10 is reduced as described later, the conductive ink 26 is preferably selectively transferred to the lyophilic portion 18b, and the conductive ink is easily moved from the lyophobic portion 18a to the lyophilic portion 18b when the conductive ink 26 is transferred to the first substrate 10.

[0140] The dot size of the conductive ink 26 held by the second substrate 20, that is, the size of the conductive ink droplets, is not limited. That is, the dot size of the conductive ink 26 held by the second substrate 20 may be appropriately set according to the metal pattern to be formed.

[0141] The dot size of the conductive ink 26 held by the second substrate 20 is preferably 1 to 300 μm, based on the size of the droplet before landing on the support 24 of the second substrate 20. The dot size referred to here means the longest length of the droplet in flight.

[0142] The dot size of the conductive ink 26 is preferably 1 to 300 μm in that the effect of forming the conductive ink 26 in a dotted form can be preferably obtained, the film thickness can be easily made uniform, and heating for changing the concentration of the conductive ink 26 described later can be easily controlled.

[0143] The dot size of the conductive ink 26 before landing on the support 24 of the second substrate 20 is more preferably 1 to 100 μm, and further preferably 5 to 100 μm.

[0144] The conductive ink 26 held by the second substrate 20 may be a uniform film over the entire surface, but is preferably in a pattern corresponding to the metal pattern formed on the first substrate 10 .

[0145] Therefore, the conductive ink 26 may be applied to the support 24 of the second substrate 20 on the entire surface of the support 24, but is preferably applied in accordance with the metal pattern to be formed on the first substrate 10. That is, the conductive ink 26 is preferably applied to the support 24 in accordance with the pattern of the lyophilic portion 18b to be formed on the first substrate 10.

[0146] For example, when the metal pattern formed on the first substrate 10 is in a grid shape, the conductive ink 26 held by the second substrate 20, that is, the conductive ink 26 applied to the support 24, is preferably also set to the same grid shape. In addition, when the metal pattern formed on the first substrate 10 is in a stripe shape, the conductive ink 26 held by the second substrate 20, that is, the conductive ink 26 applied to the support 24, is preferably also set to the same stripe shape. In addition, when the metal pattern formed on the first substrate 10 is a wiring pattern, the conductive ink 26 held by the second substrate 20, that is, the conductive ink 26 applied to the support 24, is preferably also set to the same wiring pattern.

[0147] This makes it possible to selectively transfer the conductive ink to the lyophilic portion 18 b of the first substrate 10 and prevent the conductive ink from adhering to the lyophobic portion 18 a , thereby forming a metal pattern with higher precision.

[0148] Furthermore, when the conductive ink 26 is applied to the support 24 of the second substrate 20 according to the metal pattern to be formed on the first substrate 10, it is also preferred that the conductive ink 26 is applied to the support 24 as droplets and the conductive ink 26 held by the second substrate 20 is provided in a dot shape as described above.

[0149] After the conductive ink 26 is applied to the support 24 of the second substrate 20, Figure 2 As shown on the right side of FIG. 2 , before the conductive ink 26 is transferred to the first substrate 10, it is preferred to adjust the conductive ink 26 held by the second substrate 20 on the support 24. Figure 2 As shown on the right side of FIG. 2 , the conductive ink 26 is conditioned by heating using a heater H, for example.

[0150] Examples of the adjustment of the conductive ink 26 include adjustment of viscosity, adjustment of surface tension, adjustment of concentration, adjustment of temperature, adjustment of film thickness, and adjustment of dot size in the case of dot-shaped conductive ink 26 .

[0151] Among them, as adjustment of the conductive ink 26 , preferably, for example, adjustment of viscosity, adjustment of surface tension, and adjustment of concentration can be mentioned.

[0152] For example, increasing the viscosity of the conductive ink 26 held by the second substrate 20 is preferred in terms of uniformly applying the conductive ink 26 without unnecessary spreading. Reducing the viscosity of the conductive ink 26 is preferred in terms of making the droplets of the conductive ink 26 smaller when applying the conductive ink 26 in droplets, making it easier to adjust and change the transferability, etc.

[0153] For example, it is preferable to reduce the surface tension of the conductive ink 26 held by the second substrate 20 in order to facilitate the conductive ink 26 to move from the lyophobic portion 18 a to the lyophilic portion 18 b in the first substrate 10 .

[0154] For example, increasing the concentration of the conductive ink 26 held by the second substrate 20 is preferable in that a metal pattern with high conductivity can be formed, and the thickness of the metal pattern such as wiring can be changed.

[0155] The conductive ink 26 may be conditioned by a known method depending on the conductive ink 26 and the object of conditioning of the conductive ink 26, that is, which one is to be conditioned. Specifically, heating and light irradiation such as ultraviolet irradiation may be exemplified.

[0156] For example, by heating the conductive ink 26 held by the second substrate 20 , the solvent or dispersion medium can be evaporated, the conductive ink 26 can be highly concentrated, the viscosity of the conductive ink 26 can be increased, and the surface tension of the conductive ink 26 can be reduced.

[0157] The method for heating the conductive ink 26 is not limited, and a known method can be used. As an example, the method for heating the conductive ink 26 can be exemplified as follows: Figure 2 The heating shown includes heating using a heater H, heating using hot air, heating using microwaves, heating using the support 24, and the like.

[0158] The heating temperature of the conductive ink 26 is not limited, and may be appropriately set within a range that does not adversely affect the conductive ink 26 and the support 24, depending on the type of solvent or dispersion medium used for the conductive ink 26, the material forming the support 24, and the like. The conductive ink 26 is preferably heated so that the temperature of the conductive ink 26 becomes 25 to 100° C., more preferably 30 to 90° C., and even more preferably 40 to 80° C.

[0159] Furthermore, the conductive ink 26 before transfer to the second substrate 20 needs to be conditioned so that the conditioned conductive ink 26 maintains fluidity as a liquid.

[0160] After the first substrate 10 having the affinity pattern formed thereon and the second substrate 20 holding the conductive ink 26 are prepared as described above, Figure 3 As shown in the left and center of the figure, the affinity pattern 18 of the first substrate 10 is opposed to the conductive ink 26 of the second substrate 20, and the first substrate 10 is in contact with the second substrate 20. More specifically, the affinity pattern 18 of the first substrate 10 is in contact with the conductive ink 26 of the second substrate 20.

[0161] As a result, the conductive ink 26 is transferred from the second substrate 20 to the lyophilic portion 18 b of the first substrate 10 .

[0162] In the method for forming a metal pattern of the present invention, the conductive ink 26 is not directly applied to the substrate having the affinity pattern formed thereon, but is supplied to the first substrate 10 having the affinity pattern 18 formed thereon by transfer from the second substrate 20 as described above.

[0163] By having such a structure, the present invention can prevent the conductive ink 26 from adhering to the lyophobic portion 18 a and selectively supply the conductive ink 26 to the lyophilic portion 18 b to form a high-precision metal pattern.

[0164] It is known that a metal pattern such as a wiring pattern is formed by applying a conductive ink only to the lyophobic portion of a substrate using a affinity pattern. However, in the conventional method of forming a metal pattern using an affinity pattern, the conductive ink attached to the lyophobic portion sometimes remains, resulting in unnecessary metal attachment to the substrate.

[0165] In this regard, the present inventors have conducted intensive studies and found that when the conductive ink is applied to a substrate, if there is excess conductive ink, the conductive ink is less likely to adhere to the lyophilic portion of the affinity pattern and is more likely to remain in the lyophobic portion.

[0166] For example, in the coating of conductive ink by the doctor blade method, unnecessary conductive ink that bounces up in the lyophobic portion is removed by the doctor blade as described in Patent Document 2. Therefore, the doctor blade method is considered to be a coating method in which conductive ink is less likely to remain in the lyophobic portion.

[0167] Here, when the conductive ink is thinly applied to the substrate using a doctor blade method, the conductive ink peels off from the meniscus formed on the doctor blade and passes through the lyophilic portion while forming small droplets. The conductive ink is supplied to the lyophilic portion in a flowing manner from the droplets.

[0168] Therefore, if the amount of conductive ink applied is large and the surface tension of the liquid is high, the size of the droplet when it is first peeled off from the meniscus becomes larger, causing the surface tension of the liquid to be greater than the force of wetting and diffusion toward the lyophilic part, and it will not wet and flow to the lyophilic part.

[0169] This phenomenon becomes more significant as the pattern of the lyophilic portion becomes finer, that is, as an attempt is made to form a finer metal pattern.

[0170] That is, according to the research of the present inventors, in order to prevent the conductive ink from adhering to the lyophobic part of the substrate formed with the affinity-disappearance pattern, the coating thickness must be reduced when the conductive ink is applied to the lyophilic part. In addition, the conductive ink with low surface tension must be used.

[0171] However, the materials of the conductive ink are also limited. For example, water is preferably used as a solvent and dispersion medium for the conductive ink, but there is a limit to how much the surface tension can be reduced in the conductive ink using water.

[0172] Furthermore, even if the conductive ink can be applied entirely, the resistance will not be reduced if the density of the metal in the conductive ink is low. That is, a liquid having a solid content concentration above a certain predetermined level must be supplied, so there is a limit to the adjustment of physical properties.

[0173] That is, the present inventors have found that the design on the supply side of the conductive ink is also important.

[0174] The present invention has been completed by obtaining such knowledge, and uses the second substrate 20 holding the conductive ink 26 to transfer the conductive ink 26 from the second substrate 20 to the first substrate 10 having the hydrophilic pattern 18 having the lyophobic portion 18a and the lyophilic portion 18b formed thereon.

[0175] In the present invention, the conductive ink 26 is held by the second substrate 20 . When the conductive ink 26 contacts the lyophobic portion 18 a of the first substrate 10 , the conductive ink 26 is repelled by the lyophobicity of the lyophobic portion 18 a and remains on the second substrate 20 .

[0176] On the other hand, even if the conductive ink 26 remains on the second substrate 20, the conductive ink 26 abutting against the lyophilic portion 18b is transferred from the second substrate 20 to the lyophilic portion 18b by the lyophilicity, i.e., wettability, of the lyophilic portion 18b. Furthermore, the conductive ink 26 of the second substrate 20 abutting against and repelling the lyophobic portion 18a also moves from the lyophobic portion 18a to the lyophilic portion 18b by the surface tension of the conductive ink 26.

[0177] Furthermore, since the conductive ink 26 is transferred from the second substrate 20 , the amount of the conductive ink 26 supplied to the first substrate 10 can be reduced compared to the case where the conductive ink is applied to the first substrate 10 .

[0178] Furthermore, the conductive ink 26 is held on the second substrate 20 having no affinity pattern. Therefore, according to the present invention, the conductive ink 26 can be subjected to various treatments such as heating and light irradiation with a very high degree of freedom.

[0179] Therefore, it is preferred that Figure 2 As shown on the right side of , before being transferred to the first substrate 10, the conductive ink 26 is subjected to treatments such as high concentration and viscosity adjustment (adjustment of surface tension) by heating, thereby adjusting the state of the conductive ink 26 to an appropriate state for transfer to the first substrate 10 and forming a metal pattern.

[0180] Furthermore, since the conductive ink 26 can be adjusted on the second substrate 20 , nozzle clogging due to increased concentration and deterioration of coating properties due to increased viscosity have no influence on the coating device that applies the conductive ink 26 to the second substrate 20 .

[0181] That is, according to the method of forming a metal pattern of the present invention using transfer from the second substrate 20 , the conductive ink 26 can be prevented from adhering to the lyophobic portion 18 a and the conductive ink 26 can be selectively supplied to the lyophilic portion 18 b to adhere thereto.

[0182] As a result, according to the method for forming a metal pattern of the present invention, metal is prevented from being attached to unnecessary portions of the substrate and metal is selectively supplied to the portion where the metal pattern is to be formed, thereby making it possible to form a high-precision metal pattern on the substrate even if the pattern is fine.

[0183] In the method for forming a metal pattern of the present invention, the first substrate 10 and the second substrate 20 are basically brought into contact by placing the affinity pattern 18 of the first substrate 10 and the conductive ink 26 of the second substrate 20 opposite to each other to stack the first substrate 10 and the second substrate 20. However, when the conductive ink 26 held by the second substrate 20 corresponds to the affinity pattern 18, the first substrate 10 and the second substrate 20 are aligned to be stacked.

[0184] Here, the contact between the first substrate 10 and the second substrate 20 is, to be precise, the contact between the affinity pattern 18 of the first substrate 10 and the conductive ink 26 held by the second substrate 20. Therefore, when the first substrate 10 and the second substrate 20 are stacked, a known spacer can be used to adjust the interval between the support 12 of the first substrate 10 and the support 24 of the second substrate 20 as needed. The interval between the support 12 and the support 24 can be appropriately set according to the film thickness of the conductive ink 26 held by the second substrate or the height of the dots so that the conductive ink 26 is not applied and spread unnecessarily due to pressing.

[0185] Furthermore, when the first substrate 10 and the second substrate 20 are in contact with each other, it is preferable that the temperature of the first substrate 10 be higher than the temperature of the second substrate 20 .

[0186] This is preferable in that excessive heating of the second substrate 20 can be prevented, the heating efficiency of the conductive ink 26 can be improved, and the conductive ink 26 can be dried quickly.

[0187] In this way, after the conductive ink 26 is transferred from the second substrate 20 to the first substrate 10, Figure 3 As shown on the right side of , the second substrate 20 is removed.

[0188] Thereafter, the conductive ink 26 is dried to produce the first substrate 10 on which the metal pattern 30 is formed. Drying may be performed by a known method corresponding to the conductive ink 26, such as heat drying.

[0189] After the conductive ink 26 is dried, the first substrate 10 may be cleaned as necessary. Cleaning may be performed by a known method such as cleaning with a solvent or a dispersion medium of the conductive ink 26.

[0190] After the conductive ink 26 is dried, it may be cured by heating, sintering, or ultraviolet irradiation as necessary to obtain the first substrate 10 having the metal pattern 30 formed thereon. The first substrate 10 may be cleaned thereafter.

[0191] Figure 1 to Figure 3 In the conductive pattern forming method of the present invention shown above, the conductive ink 26 is transferred to the first substrate 10 using the sheet-like second substrate 20 , but the present invention is not limited thereto, and various forms of second substrates can be used.

[0192] As an example, it can be exemplified as follows Figure 4 The second substrate 40 is conceptually shown in a roll shape.

[0193] Figure 4In the example shown, a coating device 42 for coating the conductive ink on the rotating second substrate 40 and a processing device 46 for adjusting the state of the conductive ink held by the second substrate 40 by heating or the like are provided around the second substrate 40 .

[0194] In the example shown in the figure, the long first substrate 10 is brought into contact with the second substrate 40 in synchronization with the rotation speed (peripheral speed) of the second substrate 40 and is transported in the longitudinal direction.

[0195] The conductive ink is applied to the rotating second substrate 40 by the coating device 42 , and the conductive ink is processed by the processing device 46 such as condensation.

[0196] Thus, the conductive ink can be continuously transferred to the second substrate 20 in contact with the long first substrate 10 while the long first substrate 10 is transported in the longitudinal direction.

[0197] Therefore, by using the roll-shaped second substrate 40 , the conductive ink is continuously applied to the first substrate 10 in a so-called roll-to-roll method, so that a metal pattern can be formed and high productivity can be obtained.

[0198] At this time, the conveying speed of the first substrate 10 is not limited and may be appropriately set according to the metal pattern to be formed, the affinity pattern 18 of the first substrate 10 , the type of the conductive ink, and the like.

[0199] Considering the transfer of the conductive ink to the first substrate 10 and productivity, the conveying speed (circumferential speed) of the second substrate 40 is preferably 0.1 to 100 m / min, more preferably 0.5 to 20 m / min, and further preferably 1 to 10 m / min.

[0200] In the embodiment using the roll-shaped second substrate 40 , the first substrate 10 is not limited to a long length, and the conductive ink can be continuously transferred to a plurality of first substrates 10 using a slice-shaped first substrate 10 , for example.

[0201] As mentioned above, the method for forming a metal pattern of the present invention has been described in detail, but the present invention is not limited to the above-mentioned embodiment, and various improvements or changes can be made without departing from the gist of the present invention.

[0202] Example

[0203] Hereinafter, the present invention will be specifically described with reference to Examples. In addition, the present invention is not limited to the specific Examples shown below.

[0204] [Example 1]

[0205] <Preparation of the first substrate>

[0206] A PET film (A4100 manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was cut into 10×10 cm, and a silicon nitride film was formed on the surface of the PET film not having the primer layer using a conventional plasma CVD apparatus, thereby obtaining a support body of the first substrate.

[0207] OPTOOL manufactured by DAIKIN INDUSTRIES, LTD. was applied to the surface of the silicon nitride film of the support by spin coating to a thickness of 5 nm. The coating was heated in an oven at 120° C. for 3 minutes to form a liquid-repellent film. The contact angle of pure water with the formed liquid-repellent film was 110°.

[0208] In addition, the contact angle of the conductive ink (manufactured by Electroninks, Inc., conductive ink EI-1104) applied to the second substrate described later was measured for the formed liquid-repellent film using a conventional contact angle meter. As a result, the contact angle between the conductive ink and the liquid-repellent film was 67°. In addition, the contact angle was measured in the same manner.

[0209] A metal mask was prepared in which 50 slit-shaped openings with a width of 10 μm were formed at intervals of 200 μm in a direction perpendicular to the longitudinal direction of the openings. The interval between the openings was the center-to-center distance in the arrangement direction.

[0210] The metal mask and the liquid-repellent film were overlapped, and vacuum ultraviolet rays were irradiated from above for 5 minutes, thereby removing the liquid-repellent film in the mask openings and replacing the exposed silicon nitride surface layer with silicon hydroxide to perform hydrophilization.

[0211] Thus, the long lyophilic sections with a width of 10 μm were arranged at intervals of 200 μm, and a first substrate having a lyophilic and lyophobic pattern was prepared in which the lyophilic sections were provided with lyophobic sections.

[0212] The contact angle between the conductive ink and the lyophilic portion was 12°. In addition, the hydrophilic pattern was fine and it was difficult to directly measure the contact angle on the first substrate. Therefore, a sample for measuring the contact angle having the lyophilic portion formed therein was prepared by irradiating the lyophilic film prepared in the same manner with vacuum ultraviolet rays under the same conditions without using a mask, and the contact angle measured by the sample was set as the contact angle between the conductive ink and the lyophilic portion of the first substrate.

[0213] <Preparation of the second substrate>

[0214] A PET film (A4100, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was cut into a size of 10×10 cm.

[0215] The surface of the primer layer without the PET film was subjected to a hydrophilic treatment using a commercially available atmospheric pressure plasma treatment apparatus, thereby obtaining a support of the second base material.

[0216] Conductive ink (EI-1104 manufactured by Electroninks, Inc., viscosity 10 cP) was applied to the atmospheric pressure plasma treated surface of the support.

[0217] For the coating of the conductive ink, ultrasonic spray (Acμmist manufactured by Sono-Tek) was used, and the frequency was controlled to 120 kHz to land the scattered droplets so that the size of the droplets was about 15 μm. In addition, the conductive ink was coated in a dotted manner while adjusting the speed so that the coating rate of the droplets in the support was about 50%, and moving the nozzle of the ultrasonic spray on the support.

[0218] The contact angle between the conductive ink and the support is 15°.

[0219] The support coated with the conductive ink was placed in an oven at 50° C. for 30 seconds to condense the conductive ink, thereby preparing a second substrate.

[0220] <Transfer process>

[0221] The affinity pattern of the first substrate is placed opposite to the conductive ink of the second substrate, and the second substrate is overlapped on the first substrate to transfer the conductive ink to the first substrate.

[0222] At this time, the gap between the two substrates was controlled so that the gap between the first substrate and the support of the second substrate was 1 to 500 μm. Specifically, a spacer made of a 10 μm PET film was sandwiched between both ends to adjust the gap.

[0223] The first substrate to which the conductive ink was transferred was heated in an oven at 120° C. for 3 minutes to dry the conductive ink, thereby forming a metal pattern.

[0224] <Evaluation>

[0225] The produced metal pattern was observed using an optical microscope, and the connectivity of the metal pattern and the non-formed portion (lyophobic portion) of the metal pattern were evaluated.

[0226] Evaluation was performed as follows.

[0227] A: All metal patterns were connected, and no metal adhesion was confirmed in the non-formed portion.

[0228] B: All metal patterns are connected, but the metal patterns are slightly disordered.

[0229] C: All metal patterns were connected, but metal was confirmed to be extremely slightly attached to the non-formed portion.

[0230] D: All metal patterns were connected, but metal adhesion was confirmed only in a part of the non-formed portion.

[0231] E: There is a portion in a part of the metal pattern where there is a possibility of failure to connect, and metal is clearly seen to adhere to the non-formed portion.

[0232] F: There is a metal pattern that is clearly unconnectable, and metal is clearly seen to be attached to the non-formed portion.

[0233] When the evaluation is A to D, it can be said that a high-precision metal pattern can be formed.

[0234] The evaluation of Example 1 was B.

[0235] [Example 2]

[0236] In the preparation of the second substrate, the second substrate was prepared in the same manner as in Example 1, except that the conductive ink was applied by bar coating (bar = 6th) to obtain a conductive ink film with a uniform thickness of 10 μm on the entire surface instead of dots.

[0237] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0238] The evaluation was performed in the same manner as in Example 1 and the evaluation was C.

[0239] [Example 3]

[0240] In the preparation of the second substrate, the second substrate was prepared in the same manner as in Example 1, except that the conductive ink used was changed to conductive ink EI-710 (viscosity 8 cP) manufactured by Electroninks.

[0241] The viscosity of the conductive ink EI-710 was almost the same as that of EI-1104 used in Example 1, but the contact angle between the first substrate and the lyophilic portion was 24° (surface tension was higher than that of 1104). The contact angle between the conductive ink and the lyophobic portion was 58.7°.

[0242] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0243] The evaluation was performed in the same manner as in Example 1 and the evaluation was C.

[0244] [Example 4]

[0245] In the preparation of the second substrate, the second substrate was prepared in the same manner as in Example 1, except that the conductive ink used was changed to conductive ink EI-1201 (viscosity 17 cP) manufactured by Electroninks.

[0246] The contact angle of the conductive ink with the lyophilic portion of the first substrate was 20°, and the surface tension (viscosity was the highest among the three) was intermediate between EI-1104 used in Example 1 and EI-710 used in Example 3. The contact angle of the conductive ink with the lyophobic portion was 63°.

[0247] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0248] The evaluation was performed in the same manner as in Example 1 and the evaluation was B.

[0249] [Example 5]

[0250] A second substrate was prepared in the same manner as in Example 1, except that the conductive ink used for preparing the second substrate was changed to conductive ink SR7000 (viscosity 10 cP) manufactured by Bando Chemical Industries, LTD.

[0251] The contact angle between the conductive ink and the lyophilic portion of the first substrate was 2°, and the lyophilicity was higher than that of the conductive inks used in Examples 1, 3, and 4. The contact angle between the conductive ink and the lyophobic portion was 59°.

[0252] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0253] The evaluation was performed in the same manner as in Example 1 and the evaluation was A.

[0254] [Example 6]

[0255] In the preparation of the second substrate, a silicon nitride film and a liquid-repellent film similar to those of the first substrate of Example 1 were formed on a PET film and used as a support. The second substrate was prepared in the same manner as in Example 1 except that this support was used.

[0256] The contact angle between the conductive ink (EI-1104) and the support (liquid-repellent film) was 67°.

[0257] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0258] The evaluation was performed in the same manner as in Example 1 and the evaluation was C.

[0259] [Example 7]

[0260] In the preparation of the second substrate, a silicon nitride film and a liquid-repellent film were formed on a PET film, which were the same as those of the first substrate in Example 1. In addition, a support was prepared by irradiating with vacuum ultraviolet rays in the same manner as in Example 1, except that no mask was used. The second substrate was prepared in the same manner as in Example 1, except that the support was used.

[0261] The contact angle between the conductive ink (EI-1104) and the support was 12°.

[0262] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0263] The evaluation was performed in the same manner as in Example 1 and the evaluation was A.

[0264] [Example 8]

[0265] The first substrate was prepared in the same manner as in Example 1 except that KY-1903 manufactured by Shin-Etsu Chemical Co., Ltd. was used as a material for forming the liquid-repellent film. The contact angle between pure water and the liquid-repellent film was 80°.

[0266] The contact angles of the conductive ink with the lyophobic and lyophilic parts of the affinity pattern of the first substrate were measured in the same manner as in Example 1. The contact angle with the lyophobic part was 80°, and the contact angle with the lyophilic part was 12°.

[0267] A metal pattern was formed in the same manner as in Example 1 except that the first substrate was used.

[0268] The evaluation was performed in the same manner as in Example 1 and the evaluation was A.

[0269] [Example 9]

[0270] In the preparation of the first substrate, a support was prepared in the same manner as in Example 1, and then the surface of the silicon nitride film was subjected to atmospheric pressure plasma treatment to render the support lyophilic. The contact angle between the conductive ink (EI-1104) and the surface of the support lyophilic was 2°.

[0271] A casting mold was prepared in which 50 long recesses with a width of 10 μm were formed at intervals of 200 μm in a direction perpendicular to the longitudinal direction of the recesses. The interval between the recesses was the center-to-center distance in the arrangement direction.

[0272] OPTOOL manufactured by DAIKIN INDUSTRIES, LTD. was applied to the convex parts of the mold, transferred to the support, and then heated in an oven at 120° C. for 3 minutes. This produced a first substrate having the same affinity pattern as in Example 1 except that the lyophilic part had a small contact angle and high lyophilicity.

[0273] A metal pattern was formed in the same manner as in Example 1 except that the first substrate was used.

[0274] The evaluation was performed in the same manner as in Example 1 and the evaluation was A.

[0275] [Example 10]

[0276] In the preparation of the first substrate, the first substrate was prepared in the same manner as in Example 1, except that the mask used when irradiating the vacuum ultraviolet rays was changed to a mask in which slit-shaped openings with a width of 5 μm were formed at intervals of 30 μm.

[0277] A metal pattern was formed in the same manner as in Example 1 except that the first substrate was used.

[0278] The evaluation was performed in the same manner as in Example 1 and the evaluation was B.

[0279] [Example 11]

[0280] In the preparation of the first substrate, the first substrate was prepared in the same manner as in Example 1, except that the mask used when irradiating the vacuum ultraviolet rays was changed to a mask in which slit-shaped openings with a width of 5 μm were formed at intervals of 30 μm.

[0281] Furthermore, a second substrate similar to that of Example 2 was prepared.

[0282] A metal pattern was formed in the same manner as in Example 1 except that the first substrate and the second substrate were used.

[0283] The evaluation was performed in the same manner as in Example 1 and the evaluation was D.

[0284] [Example 12]

[0285] In the preparation of the first substrate, the first substrate was prepared in the same manner as in Example 1, except that the mask used when irradiating the vacuum ultraviolet rays was changed to a mask in which slit-shaped openings with a width of 30 μm were formed at intervals of 500 μm.

[0286] A metal pattern was formed in the same manner as in Example 1 except that the first substrate was used.

[0287] The evaluation was performed in the same manner as in Example 1 and the evaluation was A.

[0288] [Example 13]

[0289] In the preparation of the first substrate, the first substrate was prepared in the same manner as in Example 1, except that the mask used when irradiating the vacuum ultraviolet rays was changed to a mask in which slit-shaped openings with a width of 30 μm were formed at intervals of 500 μm.

[0290] Furthermore, a second substrate similar to that of Example 2 was prepared.

[0291] A metal pattern was formed in the same manner as in Example 1 except that the first substrate and the second substrate were used.

[0292] The evaluation was performed in the same manner as in Example 1 and the evaluation was C.

[0293] [Example 14]

[0294] In the preparation of the second substrate, the second substrate was prepared in the same manner as in Example 1, except that the final concentration of the conductive ink was changed to being carried out in an oven at 25° C. for 30 seconds.

[0295] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0296] The evaluation was performed in the same manner as in Example 1 and the evaluation was C.

[0297] [Example 15]

[0298] In the preparation of the second substrate, the second substrate was prepared in the same manner as in Example 1, except that the final concentration of the conductive ink was changed to being carried out in an oven at 80° C. for 30 seconds.

[0299] A metal pattern was formed in the same manner as in Example 1 except that the second substrate was used.

[0300] The evaluation was performed in the same manner as in Example 1 and the evaluation was C.

[0301] [Comparative Example 1]

[0302] As a substrate on which a metal pattern is to be formed, a substrate similar to the first substrate of Example 1 was prepared.

[0303] The same conductive ink as in Example 1 was dripped onto the affinity-dissipation pattern-forming surface of the substrate and then coated on the entire surface using a doctor blade method.

[0304] The substrate was prepared in the same manner as in Example 1, and the conductive ink was dried by heating in an oven at 120° C. for 3 minutes, thereby forming a metal pattern.

[0305] The evaluation was performed in the same manner as in Example 1 and the evaluation was F.

[0306] [Comparative Example 2]

[0307] As a substrate on which a metal pattern is to be formed, a substrate similar to the first substrate of Example 1 was prepared.

[0308] In the same manner as in the second substrate of Example 1, the same conductive ink as in Example 1 was spray-coated on the affinity-repulsion pattern-formed surface of the substrate.

[0309] The substrate was prepared in the same manner as in Example 1, and the conductive ink was dried by heating in an oven at 120° C. for 3 minutes, thereby forming a metal pattern.

[0310] The evaluation was performed in the same manner as in Example 1 and the evaluation was E.

[0311] The results are summarized in the following table.

[0312] [Table 1]

[0313]

[0314] In this table, the contact angle is the contact angle of the conductive ink.

[0315] As shown in the above table, according to the present invention in which a metal pattern is formed on a first substrate by applying a conductive ink to a second substrate and transferring the conductive ink to the first substrate, a high-precision metal pattern can be formed compared to a comparative example in which a metal pattern is formed by directly applying a conductive ink to a substrate having a affinity pattern formed thereon in the same manner as the first substrate.

[0316] Furthermore, as shown in Examples 1 and 2 and Examples 10 to 13, by forming the conductive ink held by the second substrate in a dot shape instead of a uniform film, a metal pattern with higher precision can be formed.

[0317] As shown in Examples 3 to 5, by increasing the lyophilicity in the lyophilic portion of the lyophilic pattern of the first substrate, a metal pattern with higher precision can be formed.

[0318] As shown in Examples 6 and 7, by increasing the lyophilicity of the support of the second substrate, a metal pattern with higher precision can be formed.

[0319] As shown in Examples 8 and 9, by increasing the lyophobicity of the lyophobic portion in the lyophobic pattern of the first substrate and increasing the lyophilicity of the lyophilic portion, a metal pattern with higher precision can be formed.

[0320] Furthermore, as shown in Example 1, Example 14, and Example 15, on the second substrate, by heating the conductive ink at an appropriate temperature, a metal pattern with higher precision can be formed.

[0321] The above results show that the present invention has obvious effects.

[0322] Industrial Applicability

[0323] The present invention can be preferably used for forming wiring patterns in various devices.

[0324] Explanation of symbols

[0325] 10-first substrate, 12, 24-support, 14-liquid-repellent film, 16-mask, 18-liquid-philic pattern, 18a-liquid-repellent portion, 18b-liquid-philic portion, 20, 40-second substrate, 26-conductive ink, 30-metal pattern, 42-coating device, 46-processing device, UV-light source, H-heater.

Claims

1. A method for forming a metal pattern, comprising: forming a metal pattern on a substrate using a liquid containing a metal component; a step of preparing a first substrate, the first substrate having a lyophilic portion and a lyophobic portion, the lyophilic portion being lyophilic to the metal component-containing liquid and corresponding to the metal pattern to be formed, and the lyophobic portion being lyophobic to the metal component-containing liquid; a step of preparing a second substrate, wherein the second substrate is coated with and retains the metal component-containing liquid on a surface thereof according to the metal pattern to be formed on the first substrate; and The transfer step is to place the first substrate in contact with the second substrate and transfer the metal component-containing liquid from the second substrate to the lyophilic portion of the first substrate.

2. The method for forming a metal pattern according to claim 1, wherein: The second substrate is in a roll shape.

3. The method for forming a metal pattern according to claim 1 or 2, wherein: The second substrate holds the metal component-containing liquid in a dotted form.

4. The method for forming a metal pattern according to claim 1 or 2, wherein: The contact angle between the metal component-containing liquid and the lyophilic portion of the first substrate is 15° or less. A contact angle between the metal component-containing liquid and the lyophobic portion of the first substrate is 70° or greater.

5. The method for forming a metal pattern according to claim 1 or 2, wherein: A difference between a contact angle between the metal component-containing liquid and the lyophilic portion of the first substrate and a contact angle between the metal component-containing liquid and the lyophobic portion is 70° or more.

6. The method for forming a metal pattern according to claim 1 or 2, wherein: The surface tension of the metal component-containing liquid at 25° C. is 22 to 35 dyn / cm.

7. The method for forming a metal pattern according to claim 1 or 2, wherein: The first substrate is set at a higher temperature than the second substrate, and the first substrate is brought into contact with the second substrate.

8. The method for forming a metal pattern according to claim 1 or 2, wherein: The metal component-containing liquid is an aqueous solution of metal particles or metal compounds, or a dispersion in which metal particles or metal compounds are dispersed in water.

9. The method for forming a metal pattern according to claim 1 or 2, wherein: Before the first substrate and the second substrate come into contact with each other, the metal component-containing liquid held by the second substrate is adjusted.

10. The method for forming a metal pattern according to claim 9, wherein: The adjustment of the metal component-containing liquid is one or more of adjustment of viscosity, adjustment of surface tension, and adjustment of concentration.

11. The method for forming a metal pattern according to claim 1 or 2, wherein: The second substrate holds the metal component-containing liquid applied in a dotted manner, The metal component-containing liquid held in the dot form on the second substrate is directly transferred from the second substrate to the lyophilic portion of the first substrate.

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