JP2018148040A - Conductive pattern forming method - Google Patents

Abstract

An object of the present invention is to provide a method for forming a conductive pattern, which has a small number of breaks in the obtained conductive pattern and is excellent in light transmittance. A step of preparing a printing plate having a concave line on the surface, a step of holding plating-forming ink in a concave portion of the concave line, a step of transferring the plating-formable ink held in the concave portion to a substrate, And a step of forming plating on the plating-forming ink transferred to the base material, wherein the line width of the concave line is less than 20 μm, and the line width is obtained from the depth of the concave line / the line width of the concave line. A conductive pattern forming method, wherein the aspect ratio, which is a value to be obtained, is more than 0.5 and 7 or less. [Selection diagram] FIG.

Description

  The present disclosure relates to a conductive pattern forming method.

Conventionally, conductive patterns by printing have been widely used in various fields as various sensors such as pressure sensors and biosensors, printed boards, solar cells, capacitors, electromagnetic wave shields, touch panels, antennas and the like.
Examples of conventional conductive pattern forming methods include the methods described in Patent Documents 1 to 4.
Patent Document 1 discloses a method for forming a fine line pattern having a line width of 1 to 60 μm on one surface of a flexible base material with a conductive paste, which is formed on the surface of a gravure cylinder of a gravure printing machine. A conductive paste is press-fitted into the mold groove of the fine line pattern of the plate with a doctor blade, and viewed from the rotation axis direction of the gravure cylinder, the gravure cylinder at a position of 45 to 180 degrees clockwise or counterclockwise from the upper end. A method for forming a fine line pattern is described in which line contact is made with a transfer material, and the conductive paste is transferred from the gravure plate to the transfer material at the line contact position.

In Patent Document 2, the surface of an ink resin printed with a circuit pattern on a substrate is coated with a colloidal solution in which conductive nanometal powder having an average particle size of 0.1 nm to 50 nm is dispersed, and then the colloidal solution is used. And the ink resin is heated to evaporate the liquid in the colloidal solution, fuse the conductive nanometal powders together, and form a conductive metal film on the surface of the ink resin to be heat-cured. A circuit manufacturing method characterized by the above is described.
In Patent Document 3, a conductive pattern is formed by forming a net-like pattern having an average line width of 50 μm or less made of a resin composition on a transparent substrate by a gravure printing method, and providing a metal layer on the pattern. A method for producing a transparent electromagnetic wave shielding material is described.
Patent Document 4 discloses a method of manufacturing a printed circuit board on an insulating carrier (2), in which a circuit pattern (1) is formed on the carrier using a conductive ink, and then the carrier is plated. And a method characterized in that the conductive ink is added by a gravure printing method.

JP 2010-258381 A JP 2004-172288 A JP 2003-304090 A JP-T-2004-529499

Conventionally, when the conductive pattern is formed by screen printing, the line width is usually 50 μm to 70 μm and the line width of 50 μm or less is difficult due to the accuracy of finishing the opening width of the opening hole pattern.
Further, when the conductive pattern is formed by letterpress printing (flexographic printing), since the plate is soft, the plate is crushed by printing, and the line width tends to be thick, and the line width is usually more than 20 μm and not more than 30 μm, Further, since the ink is thin, there is a problem in that disconnection is likely to occur when a fine line is printed.
When a conductive pattern is formed by lithographic printing, the line width possible at the mass production level is 50 μm or more, and, as with letterpress printing, the thickness of the ink is so thin that it tends to cause disconnection when printing fine lines. Furthermore, since the ink is transferred to the base material via the blanket, there is a problem that unevenness of the printing pattern, increase in line width, disconnection, etc. are likely to occur in response to the change of the blanket state over time. there were.

  The problem to be solved by an embodiment of the present invention is to provide a method for forming a conductive pattern that is less in the disconnection of the obtained conductive pattern and excellent in light transmittance.

Means for solving the above problems include the following aspects.
<1> A step of preparing a printing plate having a concave line on its surface, a step of holding a plating-formable ink in the concave portion of the concave line, a step of transferring the plating-formable ink held in the concave portion to a substrate, and Including a step of forming a plating on the plating-formable ink transferred to the substrate, wherein the line width of the concave line is less than 20 μm, and is obtained from the depth of the concave line / the line width of the concave line. The conductive pattern formation method whose aspect ratio which is a value exceeds 0.5 and is 7 or less.
<2> The conductive pattern forming method according to <1>, wherein the concave line is a concave line formed by cutting.
<3> The conductive pattern forming method according to <1> or <2>, wherein the plating formable ink includes a compound having a functional group that interacts with an electroless plating catalyst or a precursor thereof.
<4> The conductive pattern forming method according to <3>, wherein the electroless plating catalyst is an electroless copper plating catalyst.
<5> The conductive pattern forming method according to any one of <1> to <4>, wherein the concave line is a concave line formed by cutting using a cutting tool.
<6> The conductive pattern forming method according to <5>, wherein the cutting tool does not vibrate at a constant frequency in a direction perpendicular to a surface to be cut of the printing plate during cutting.
<7> The conductive pattern forming method according to any one of <1> to <6>, wherein the printing plate is a metal plate.
<8> The conductive pattern forming method according to <7>, wherein the metal plate is a metal roll.
<9> The conductive pattern forming method according to any one of <1> to <8>, wherein the concave line includes a concave line having a line width of 10 μm or less.
<10> The conductive pattern forming method according to any one of <1> to <9>, wherein the aspect ratio is more than 1.0 and 7 or less.

  According to one embodiment of the present invention, it is possible to provide a conductive pattern forming method that is less in disconnection of the obtained conductive pattern and excellent in light transmittance.

It is a cross-sectional enlarged schematic diagram which shows an example of the cross-sectional shape of the concave line vicinity part in the line width direction of the concave line formed in the surface of the printing plate used in the conductive pattern formation method which concerns on this embodiment. It is a cross-sectional enlarged schematic diagram which shows another example of the cross-sectional shape of the concave line vicinity part in the line width direction of the concave line formed in the surface of the printing plate in the conductive pattern formation method which concerns on this embodiment. It is a schematic diagram which shows an example of the flat printing plate in the conductive pattern formation method which concerns on this embodiment. FIG. 4 is a partial schematic enlarged view including a concave line 106 in an elliptical portion 108 shown in FIG. 3. FIG. 4 is a partial schematic enlarged view including a concave line 106 of another shape in the elliptical portion 108 shown in FIG. 3. FIG. 4 is a partial schematic enlarged view including a concave line 106 of another shape in the elliptical portion 108 shown in FIG. 3. FIG. 4 is a partial schematic enlarged view including a concave line 106 of another shape in the elliptical portion 108 shown in FIG. 3. FIG. 4 is a partial schematic enlarged view including a concave line 106 of another shape in the elliptical portion 108 shown in FIG. 3. It is a schematic diagram which shows an example of the other flat plate-shaped printing plate in the conductive pattern formation method which concerns on this embodiment. FIG. 10 is a partial schematic enlarged view including a concave line 106 in the elliptical portion 108 </ b> A shown in FIG. 9. FIG. 10 is a partial schematic enlarged view including a concave line 106 in the elliptical portion 108 </ b> B shown in FIG. 9.

Hereinafter, the contents of the present disclosure will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.
In the specification of the present application, “to” indicating a numerical range is used in a sense including numerical values described before and after the numerical value as a lower limit value and an upper limit value.
Moreover, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
In this specification, “(meth) acryl” is a term used in a concept including both acryl and methacryl, and “(meth) acryloyl” is a term used as a concept including both acryloyl and methacryloyl. It is.
In addition, the term “process” in this specification is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term is used as long as the intended purpose of the process is achieved. included. In the present disclosure, “mass%” and “wt%” are synonymous, and “part by mass” and “part by weight” are synonymous.
Furthermore, in the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.
Hereinafter, the present disclosure will be described in detail.

(Conductive pattern forming method)
The conductive pattern forming method according to the present disclosure includes a step of preparing a printing plate having a concave line on a surface, a step of holding a plating-formable ink in a concave portion of the concave line, and a plating-formable ink held in the concave portion. Including a step of transferring to a base material, and a step of forming plating on the plating-formable ink transferred to the base material, wherein the line width of the concave line is less than 20 μm, and the depth of the concave line / the above-mentioned The aspect ratio, which is a value obtained from the line width of the concave line, is more than 0.5 and 7 or less.

As a result of intensive studies by the present inventors, it has been found that by taking the above-described configuration, it is possible to provide a method for forming a conductive pattern that is less in the disconnection of the obtained conductive pattern and is excellent in light transmittance.
Although the mechanism of the excellent effect by this is not clear, it is estimated as follows.
Because of the intaglio, the amount of ink transferred is larger than that of letterpress and lithographic plates. Therefore, when printing fine patterns, even if the intaglio line width is narrow, disconnection is less likely to occur, and the resulting conductive pattern is light transmissive. It is presumed that the resistance is low because it is excellent in conductivity and imparts conductivity by plating.
In addition, the indentation of the intaglio plate is formed by an electronic engraving (for example, paragraphs 0081 of JP-T-2015-506289 and columns 7 to 8 of JP-B 62-17540). And the line width is less than 20 μm, and the aspect ratio (depth / line width) between the line width and the depth is 0. By forming with a printing plate having a concave line exceeding 5 and not more than 7 on the surface, a concave line with a narrow line width can be easily formed with little disconnection, and light transmission of the resulting conductive pattern It is estimated that it is excellent in performance.

<Process to prepare>
The conductive pattern forming method according to the present disclosure includes a step of preparing a printing plate having concave lines on the surface.
The concave line on the surface of the printing plate used in the present disclosure is preferably formed by cutting from the viewpoint of wire breakage suppression, light transmittance, and low resistance.
“Cutting” in the present disclosure is different from the above-described electronic engraving for engraving the cells, and a processing tool (for example, a bite) described later is brought into contact with the surface of the printing plate precursor to form a desired concave surface of the printing plate precursor. It is a process to scrape off. Note that the printing plate precursor in the present disclosure refers to an uncut substrate. For example, in a direction perpendicular to the surface of the printing plate precursor, the processing tool is preferably processed as a concave line shape without being processed into a cell shape by vibrating at a constant frequency. In the concave portion formed by the engraving described above, the line width of the obtained conductive pattern is large and the light transmittance is inferior, and the shape of the concave portion of the obtained conductive pattern is not stable, resulting in increased disconnection.
Further, in the above-described cutting, the shape of the portion to be cut in contact with the processing tool is preferably at least twice as long as the line width of the recess, and more than 5 times as long as the line width of the recess. More preferably.

The printing plate used in the present disclosure preferably has a cuttable surface, and has a metal layer on the surface from the viewpoints of machinability, printability, and durability, that is, a metal plate. Preferably, it has a copper, copper alloy, nickel or nickel alloy layer, more preferably has a copper or nickel layer on its surface, and most preferably has a copper or nickel plating layer on its surface.
Further, from the viewpoint of durability, the copper or nickel (plating) layer has a surface hardened layer of either a chromium plating layer or a diamond-like carbon (DLC) layer on at least a part of its surface. It is preferable to have a chromium plating layer.

The thickness of the metal layer is not particularly limited, but is preferably 20 μm or more and 1,000 μm or less, more preferably 30 μm or more and 300 μm or less, and 40 μm from the viewpoints of machinability, printability, and durability. The thickness is particularly preferably 200 μm or more.
The thickness of the surface hardened layer is preferably from 0.1 μm to 20 μm, more preferably from 0.1 μm to 10 μm, and more preferably from 0.2 μm to 5 μm from the viewpoint of durability. It is particularly preferred.

The form of the printing plate used in the present disclosure may be a flat surface or a roll. Moreover, it is good also as a roll, after cutting a flat printing plate precursor.
The material of the flat plate precursor used in the present disclosure is not particularly limited, but the flat plate precursor is preferably a metal plate, a group consisting of copper, copper alloy, nickel and nickel alloy. More preferably, the plate is made of a material selected from.
There is no restriction | limiting in particular in the material of the core material in the printing roll used for this indication, A well-known gravure printing roll can be used, A metal roll is mentioned preferably from a viewpoint of cost and durability.
Moreover, it is preferable that the core material of the printing roll is iron or aluminum from the viewpoint of cost and durability.
The width, outer diameter, inner diameter and the like of the printing roll are not particularly limited and can be appropriately set as desired.

The shape of the concave line is not particularly limited, but the cross-sectional shape of the concave line in the line width direction is an inverted triangle, a rectangle, or an inverted trapezoid from the viewpoint of suppressing disconnection of the obtained conductive pattern and light transmittance. Is more preferable, an inverted triangle or a rectangle is more preferable, and an inverted triangle is particularly preferable. Moreover, the tip of the inverted triangle may be rounded.
Moreover, the concave line formed in the said printing plate can be formed not only in a linear concave line but in arbitrary pattern shapes.
Further, the number of the concave lines is not particularly limited, and a desired number can be formed.
Further, the pitch interval of the concave lines is not particularly limited, and the concave lines may be formed at a desired interval, but is preferably 5 μm to 2,000 μm, and more preferably 10 μm to 1,000 μm. .

The concave line has a line width of 20 μm or less, and preferably has a line width of 10 μm or less from the viewpoint of light transmittance of the obtained conductive pattern.
In addition, the concave line preferably includes a concave line having a line width of 10 μm or less, and includes a concave line having a line width of 0.3 μm or more and 10 μm or less, from the viewpoint of light transmittance of the obtained conductive pattern. More preferably, it includes a concave line having a line width of 0.4 μm to 8 μm, and particularly preferably includes a concave line having a line width of 0.5 μm to 6 μm.
The depth of the concave line is preferably 0.2 μm or more and 40 μm or less, more preferably 0.3 μm or more and 30 μm, from the viewpoint of suppression of disconnection of the obtained conductive pattern and light transmittance. More preferably, it is 4 μm or more and 25 μm or less, and particularly preferably 0.5 μm or more and 20 μm or less.

The aspect ratio (depth / line width) which is a value obtained from the depth of the concave line / the line width of the concave line is more than 0.5 and 7 or less, and more than 0.5 and 5 or less. Is more preferable, 0.8-4 is further preferable, and 0.8-3 is particularly preferable. Within the above range, the amount of conductive ink retained is sufficient, the amount transferred to the substrate is sufficient, the occurrence of disconnection is suppressed, and a conductive pattern with lower resistance and better light transmission is obtained. Moreover, it is possible to suppress the conductive ink from remaining in the concave line during the transfer of the conductive ink to the base material, and cleaning after printing is easy.
In addition, the aspect ratio (depth / line width) between the line width and the depth, which is a value obtained from the depth of the concave line / the line width of the concave line (depth / line width) is determined by controlling the disconnection of the obtained conductive pattern and the line width. From the viewpoint of suppressing variation, it is preferably more than 1.0 and 7 or less, more preferably 1.2 or more and 7 or less, further preferably 1.5 or more and 7 or less, and 2.0 or more. Particularly preferred is 6.0 or less.

FIG. 1 is an enlarged schematic cross-sectional view showing an example of a cross-sectional shape of a portion near the concave line in the line width direction of the concave line formed on the surface of the printing plate used in the conductive pattern forming method according to the present embodiment.
The concave line 10 formed on the surface of the printing plate shown in FIG. 1 has an inverted triangle cross-sectional shape in the line width direction of the concave line, and is formed by cutting a metal layer 12 such as a copper or nickel layer.
Moreover, the depth 14 and the line width 16 in the concave line 10 are shown in FIG.
The line width of the concave line in the present disclosure is the length (width) of the opening in the direction perpendicular to the line direction of the concave line on the printing plate surface as shown in FIG. The direction is a direction perpendicular to the concave line direction in the surface direction of the printing plate. Further, the depth of the concave line in the present disclosure is a cutting depth, and represents a distance from a point in the concave portion farthest from a line connecting two end points in the line width direction of the concave line on the printing plate surface. 1 corresponds to the depth 14 in the cross-sectional shape of the concave line in the line width direction.

FIG. 2 is an enlarged schematic cross-sectional view showing another example of the cross-sectional shape of the portion near the concave line in the line width direction of the concave line formed on the surface of the printing plate in the conductive pattern forming method according to the present embodiment. is there.
The surface of the printing plate shown in FIG. 2 has a hardened surface layer 18, and the concave line 10 formed on the surface of the printing plate has an inverted triangular cross-sectional shape in the line width direction. A metal layer 12 such as a copper or nickel layer is cut and formed, and a surface hardened layer 18 is formed on the surface thereof.
Moreover, the depth 14 and the line width 16 in the concave line 10 are shown in FIG.

As a method for forming a concave line on the surface of the printing plate by cutting, a method using a cutting tool is preferably mentioned from the viewpoint of wire breakage suppression, light transmittance, and low resistance.
Examples of the bite include diamond (single crystal), diamond sintered body (polycrystal), cubic boron nitride (cBN) sintered body, ceramics, cermet, cemented carbide, high speed steel (high speed), and coated. However, single crystal diamond is preferable from the viewpoint of processing accuracy.
In addition, the cutting tool preferably has a V-shaped cutting tool, that is, the cutting surface of the cutting tool (the surface contacting the workpiece) is preferably V-shaped, and the V-shaped angle is More preferably, the angle is 90 degrees (90 °) or less, the V-shaped angle is more preferably 75 degrees or less, and the V-shaped angle is particularly preferably 15 degrees or more and 65 degrees or less. .
Furthermore, it is preferable that the cutting tool does not vibrate at a constant frequency in a direction perpendicular to the surface to be cut of the printing plate during cutting. In a direction perpendicular to the surface to be cut of the printing plate, such as engraving, in a direction perpendicular to the surface to be cut of the printing plate during cutting, as compared with an aspect in which cutting is performed by vibrating a cutting tool at a constant frequency. In this case, the cross-sectional shape of the concave line due to the cutting is stabilized, the disconnection of the obtained conductive pattern is further suppressed, and the concave line can be made a finer wire. The light transmittance of the pattern is more excellent.

<Holding process>
The conductive pattern forming method according to the present disclosure includes a step of holding a plating-forming ink in the concave portion of the concave line.
The amount of the plating-formable ink retained in the recess is not particularly limited as long as it can sufficiently form a conductive pattern in the transfer and plating formation described below.
There is no restriction | limiting in particular as a method of hold | maintaining the plating formability ink to the said recessed part, It can use by a well-known method. Specifically, for example, there is a method in which the surface of the printing plate and the plating formable ink are brought into contact with each other, and excess plating formable ink other than the recesses is removed by a removing means such as a doctor blade.

<< Plating-forming ink >>
The plating-formable ink used in the present disclosure includes ink that can form a plating on its coating film (including dry film, cured film, etc.), or its coating film (dry film, cured film, etc.). ) Any ink may be used as long as it is an ink that can be plated by applying an electroless plating catalyst or a precursor thereof, and an electroless plating catalyst or a precursor thereof, even an ink containing an electroless plating catalyst or a precursor thereof. It may be an ink containing a compound having a functional group that interacts with the electrode (hereinafter, also referred to as “interactive group” as appropriate). From the viewpoint of wire breakage suppression and light transmittance, an electroless plating catalyst or a precursor thereof. An ink containing a compound having a functional group that interacts with the body is preferred.
The plating-formable ink preferably contains a compound having the above-mentioned interactive group and a solvent, and further contains a radical generator and a radical polymerizable compound so that it can be cured by light or heat. May be.
Examples of the interaction include formation of ionic bonds, coordination bonds, hydrogen bonds, and covalent bonds.
In addition, the plating formable ink is preferably an ink that does not contain an electroless plating catalyst from the viewpoint of fine line formability of the conductive pattern to be obtained, light transmittance, and suppression of variation in line width. More preferably, the ink does not contain.

-Electroless plating catalyst-
The electroless plating catalyst used in the present disclosure is mainly a zero-valent metal, and examples thereof include Pd, Ag, Cu, Ni, Al, Fe, and Co. In the present disclosure, Pd or Ag is particularly preferable because of its good handleability and high catalytic ability. As a method for fixing the zero-valent metal to the plating formable ink (interactive region), for example, a metal colloid whose charge is adjusted so as to interact with the interactive group of the plating formable ink is used. A technique applied to the region is used. The metal colloid can be produced by reducing metal ions in a solution containing a charged surfactant or a charged protective agent. The charge of the metal colloid can be adjusted by the surfactant or the protective agent used here, and the metal colloid whose charge has been adjusted in this way interacts with the interactive group of the plating-forming ink. Thus, the metal colloid (electroless plating catalyst) can be selectively adsorbed onto the plating-forming ink.
Among these, as the electroless plating catalyst, an electroless copper plating catalyst is preferable from the viewpoint of conductivity of the obtained conductive pattern.
The content of the electroless plating catalyst in the plating formable ink is not particularly limited, and may be 10% by mass to 95% by mass with respect to the total solid content of the plating formable ink.
In the present disclosure, the “solid content” in the composition represents a component excluding volatile components such as an organic solvent.

-Electroless plating catalyst precursor-
The electroless plating catalyst precursor used in the present disclosure can be used without particular limitation as long as it can become an electroless plating catalyst by a chemical reaction. Mainly, metal ions of zero-valent metal used in the electroless plating catalyst are used. The metal ion that is an electroless plating catalyst precursor becomes a zero-valent metal that is an electroless plating catalyst by a reduction reaction. The metal ion, which is an electroless plating catalyst precursor, may be converted into a zero-valent metal by a separate reduction reaction after being applied to the substrate and before immersion in the electroless plating bath. The plating catalyst precursor may be immersed in an electroless plating bath and changed to a metal (electroless plating catalyst) by a reducing agent in the electroless plating bath.
Moreover, it is preferable that the metal ion which is an electroless-plating catalyst precursor is provided to the ink patterned in the state of a metal salt, and is made to interact. The metal salt used is not particularly limited as long as it is dissolved in an appropriate solvent and dissociated into a metal ion and a base (anion), and M (NO ₃ ) _n , MCl _n , M _{2 / N} (SO ₄ ), M _{3 / n} (PO ₄ ) (M represents an n-valent metal atom), and the like. As a metal ion, the thing which said metal salt dissociated can be used suitably. Specific examples include Ag ions, Cu ions, Al ions, Ni ions, Co ions, Fe ions, Pd ions, and the like, and Ag ions or Pd ions are preferable in terms of catalytic ability.
Among these, as the electroless plating catalyst precursor, an electroless copper plating catalyst precursor is preferable from the viewpoint of conductivity of the obtained conductive pattern.
The content of the electroless plating catalyst precursor in the plating-formable ink is not particularly limited, and may be 1% by mass to 50% by mass with respect to the total solid content of the plating-formable ink.

-Binder resin-
When an ink containing an electroless plating catalyst or a precursor thereof is used as the plating formable ink, the plating formable ink preferably further contains a binder resin.
Binder resins include rosin resin, butyral resin, natural rubber, synthetic rubber, polyester resin, amide resin, polyether resin, vinyl resin, polyolefin resin, acrylic resin, melamine resin, epoxy resin, phenol resin, urethane resin, cellulose A derivative resin or the like can be used.
The content of the binder resin in the plating formable ink is not particularly limited, and may be 5% by mass to 90% by mass with respect to the total solid content of the plating formable ink.

-Compound having an interactive group-
The plating-forming ink used in the present disclosure preferably includes a compound having an interactive group.
Examples of the interactive group include a hydrophilic group such as a carboxyl group, a hydroxyl group, a substituted or unsubstituted amino group, a sulfonic acid group, a phosphonic acid group, and an amide group, or a salt thereof, a cyano group, an imidazole group, a pyridine group, and the like. Functional groups such as a nitrogen-containing heterocyclic group, an ether group, and an epoxy group that may have a substituent are exemplified.
Examples of the compound having an interactive group include polyacrylic acid, polymethacrylic acid, polyacrylamide, polymethacrylamide, polyacrylonitrile, acrylonitrile-butadiene-styrene (ABS) resin, and the like.

Moreover, the compound which has an interactive group, and the radically polymerizable compound may serve as the same molecule, For example, the compound which has an interactive group and a radically polymerizable group in a molecule | numerator is mentioned preferably.
Preferred examples of the compound having the interactive group and the radical polymerizable group in the molecule include acrylic resins having the interactive group and the radical polymerizable group. Moreover, a general radical polymerizable compound can be further added to the acrylic resin containing an interactive group and a radical polymerizable group in the molecule.
Examples of the acrylic resin having an interactive group and a radical polymerizable group in the molecule include a compound containing a carboxylic acid (carboxylate) described in JP-A No. 2003-118043, and described in JP-A No. 2008-257892. A compound containing a cyano group can be used.
The content of the compound having such an interactive group in the plating-formable ink is preferably 1% by mass to 50% by mass with respect to the total solid content of the plating-formable ink, and 5% by mass to 20%. More preferably, it is mass%.

-Radical generator-
The plating-formable ink used in the present disclosure preferably includes a radical generator and a radical polymerizable compound.
The radical generator may be either a thermal radical generator (thermal polymerization initiator) or a photo radical generator (photopolymerization initiator).
As the thermal radical generator, peroxide initiators such as benzoyl peroxide and azobisisobutyronitrile, and azo initiators can be used.
Examples of photo radical generators include (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (d) thio compounds, (e) hexaarylbiimidazole compounds, (f) ketoximes. Ester compounds, (g) borate compounds, (h) azinium compounds, (i) active ester compounds, (j) compounds having a carbon halogen bond, (k) pyridium compounds, and the like. It is not limited.
From the viewpoint of strength, the content of the radical generator is preferably 0.1% by mass to 50% by mass, and 1.0% by mass to 30.0% by mass with respect to the total solid content of the plating-forming ink. % Is more preferable.

-Radically polymerizable compounds-
The radical polymerizable compound used in the plating-forming ink is a compound having a radical photopolymerizable double bond (ethylenically unsaturated group), and is an acrylate compound, a methacrylate compound, a vinylbenzene compound, a bismaleimide compound. Etc. are preferable.
The (meth) acrylate compound is not particularly limited as long as it has a (meth) acryloyl group which is an ethylenically unsaturated group in the molecule, but from the viewpoint of curability and strength, a polyfunctional (meth) acrylate compound. It is preferable that
Polyfunctional ethylenically unsaturated compounds that can be suitably used in the present disclosure refer to those containing at least two ethylenically unsaturated groups in the molecule, and containing at least three ethylenically unsaturated groups in the molecule. Is preferred. The polyfunctional ethylenically unsaturated compound is preferably an ester of a polyhydric alcohol and acrylic acid or methacrylic acid.
Specific examples of the polyfunctional (meth) acrylate compound include polyfunctional (meth) acrylate compounds having 3 to 6 (meth) acrylic acid ester groups in the molecule. ) Acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, molecules having several (meth) acrylic acid ester groups in the molecule and molecular weights of several hundred to several thousand are also included in the above-mentioned plating-formable ink. It can be preferably used as a component.
Specific examples of (meth) acrylate compounds having three or more (meth) acryloxy groups in the molecule include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and pentaerythritol tri (meth) acrylate. , Polyol poly (meth) acrylates such as pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and hydroxyl groups such as polyisocyanate and hydroxyethyl (meth) acrylate ( The urethane (meth) acrylate obtained by reaction of (meth) acrylate etc. can be mentioned.
The content of the radically polymerizable compound is preferably 5% by mass to 80% by mass and preferably 10% by mass to 50% by mass with respect to the total solid content of the plating-formable ink from the viewpoint of strength. More preferred.

-Solvent-
The plating-formable ink used in the present disclosure preferably contains a solvent.
Examples of the solvent include alcohol solvents such as water, methanol, ethanol, propanol, ethylene glycol, glycerin, and propylene glycol monomethyl ether, acids such as acetic acid, ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, toluene, dodecane, and tetradecane. And hydrocarbon solvents such as cyclododecene, n-heptane and n-undecane, amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, and acetonitrile.
There is no restriction | limiting in particular in content of a solvent, What is necessary is just to select suitably according to the desired viscosity etc. in a plating formability ink.

-Viscosity of plating forming ink-
The viscosity of the plating-formable ink is preferably 1 mPa · s to 1,000 mPa · s, more preferably 5 mPa · s to 500 mPa · s, and more preferably 30 mPa · s to 200 mPa · s from the viewpoint of transferability to the substrate. Particularly preferred. In addition, as will be described later, in the case of gravure offset printing in which the plating-forming ink held in the concave portion is once transferred onto the blanket, from the viewpoint of line width and transferability from the plate to the blanket, 500 mPa · s to 100, 000 mPa · s is preferable, 1,000 mPa · s to 50,000 mPa · s is more preferable, and 5,000 mPa · s to 30,000 mPa · s is particularly preferable.

Moreover, the plating formable ink may contain other known additives.
Examples of other additives include colorants, dispersants, waxes, thickeners, thixotropy imparting agents, and the like.

<Transfer process>
The conductive pattern forming method according to the present disclosure includes a step of transferring the plating form ink held in the concave portion to a base material.
There is no restriction | limiting in particular as a transfer method in the said transfer process, The method of transferring by making a printing plate which has a recessed part with which plating-forming ink was hold | maintained by contacting a base material with a pressure is mentioned suitably.

Examples of the base material used in the present disclosure include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene and polypropylene, cyclic polyolefin resins, and cellulose derivative resins (carboxymethyl cellulose, hydroxyalkyl cellulose, Cellulose acetate, etc.), acrylic resin, epoxy resin, fluororesin, silicone resin, polycarbonate resin, diacetate resin, triacetate resin, polyarylate resin, polyvinyl chloride, polysulfone resin, polyethersulfone resin, polyimide resin, polyamide resin, polyurethane Examples thereof include resins. Among these, from the viewpoint of cost and optical properties, a polyester resin, a cyclic polyolefin resin, or a cellulose derivative resin is preferable.
There is no restriction | limiting in particular in the thickness and shape of the said base material, What is necessary is just to select suitably as needed.
The base material is preferably a roll base material.
Furthermore, the base material may be subjected to surface treatment such as corona treatment.

The conductive pattern forming method according to the present disclosure may include a step of drying the plating form ink transferred to the substrate as necessary.
The drying method is not particularly limited, and may be heat drying, air drying, or a combination thereof.
There is no restriction | limiting in particular also about a drying temperature and drying time, According to the plating forming ink etc. to be used, it can select suitably.
The film thickness of the plating formable ink is preferably 0.02 μm or more, more preferably 0.1 μm or more, and particularly preferably 0.3 μm or more from the viewpoint of plating formation.
The step of transferring the plating form ink held in the recess to the substrate includes the step of transferring the plating form ink held in the recess onto the blanket, and then transferring the ink on the blanket to the substrate. A process may be included.

<The process of providing an electroless plating catalyst or its precursor>
When an ink containing a compound having a functional group that interacts with an electroless plating catalyst or a precursor thereof is used as the plating formable ink, the conductive pattern forming method according to the present disclosure is a plating transferred to the substrate. It is preferable to include a step of applying an electroless plating catalyst or a precursor thereof on the forming ink.
As a method for applying a metal colloid as an electroless plating catalyst or a metal salt as an electroless plating precursor onto a plating-forming ink, the metal colloid is dispersed in an appropriate dispersion medium, or the metal salt is appropriately used. A solution containing metal ions dissolved and dissociated with a solvent is prepared, and the solution is applied to the surface of the substrate on which the ink pattern exists, or the substrate having the ink pattern is immersed in the solution. By contacting a solution containing a metal ion, the metal ion is adsorbed to the interacting group of the ink pattern formation region using an ion-ion interaction or a bipolar-ion interaction, or The interaction region can be impregnated with metal ions. From the viewpoint of sufficient adsorption or impregnation, the metal ion concentration or metal salt concentration of the solution to be contacted is preferably in the range of 1% by mass to 50% by mass, and 10% by mass to 30% by mass. More preferably, it is in the range. Further, the contact time is not particularly limited, but is preferably 1 minute to 24 hours, and more preferably 5 minutes to 1 hour.

<Process for forming plating>
The conductive pattern forming method according to the present disclosure includes a step of forming a plating on the plating-formable ink transferred to the substrate.
The step of forming the plating is preferably a step of forming plating on the plating-forming ink transferred to the substrate by performing electroless plating. By performing electroless plating, a high-density metal film is formed, and a conductive pattern having a lower resistance can be easily obtained.

-Electroless plating-
Electroless plating refers to an operation of depositing a metal by a chemical reaction using a solution in which metal ions to be deposited as a plating are dissolved.
The electroless plating used in the present disclosure is, for example, after rinsing the substrate on which the electroless plating catalyst is applied in a pattern to remove excess electroless plating catalyst (metal) and then immersing in an electroless plating bath It is preferable to do so. As the electroless plating bath used, a generally known electroless plating bath can be used.
In addition, when the electroless plating catalyst precursor is immersed or impregnated in the pattern in an electroless plating bath, the substrate is washed with water to remove excess electroless plating catalyst precursor (metal salt, etc.). Thereafter, it is preferably immersed in an electroless plating bath. In this case, reduction of the precursor and subsequent electroless plating are performed in the electroless plating bath. As the electroless plating bath used in this embodiment, a generally known electroless plating bath can be used as described above.

The composition of the electroless plating bath preferably includes a metal ion for plating, a reducing agent, and an additive (stabilizer) that improves the stability of the metal ion. In addition to these, the plating bath may contain known additives such as a plating bath stabilizer.
Examples of the metal used in the electroless plating bath include copper, tin, lead, nickel, gold, palladium, rhodium, tungsten, and alloys thereof. Among these, from the viewpoint of conductivity, copper or Gold is preferred and copper is particularly preferred.

Moreover, it is preferable to contain the optimal reducing agent and additive according to the said metal.
For example, a copper electroless plating bath contains Cu (SO ₄ ) ₂ as a copper salt, HCOOH as a reducing agent, and a chelating agent such as ethylenediaminetetraacetic acid (EDTA) or Rochelle salt as a copper ion stabilizer. It is preferably included.
The plating bath used for electroless plating of CoNiP includes cobalt sulfate and nickel sulfate as metal salts, sodium hypophosphite as a reducing agent, sodium malonate, sodium malate, and sodium succinate as complexing agents. Is preferably included.
The palladium electroless plating bath preferably contains (Pd (NH ₃ ) ₄ ) Cl ₂ as metal ions, NH ₃ and H ₂ NNH ₂ as reducing agents, and EDTA as a stabilizer.
These plating baths may contain components other than the above components.

The film thickness of the plating film formed in the conductive pattern forming method according to the present disclosure can be controlled by the concentration of the metal salt or metal ion in the plating bath, the immersion time in the plating bath, the temperature of the plating bath, or the like. However, from the viewpoint of conductivity, it is preferably 0.3 μm or more, more preferably 0.5 μm or more, and particularly preferably 1 μm or more.
Moreover, there is no restriction | limiting in particular as immersion time in a plating bath, However, It is preferable that it is 1 minute-3 hours, and it is more preferable that it is 1 minute-1 hour.

  Thus, a conductive pattern is formed by electroless plating.

<Process for electroplating>
The method for forming a conductive pattern according to the present disclosure may include a step of further performing electroplating using the formed plating film as an electrode after the step of forming the plating. Thus, a metal film having an arbitrary thickness can be easily formed on the conductive pattern as a base. By adding this step, the conductive film (metal film) can be formed with a thickness according to the purpose, so that a conductive pattern having desired characteristics can be formed.

As a method of electroplating, a conventionally known method can be used.
Examples of the metal used for electroplating include copper, chromium, lead, nickel, gold, silver, tin, and zinc. From the viewpoint of conductivity, copper, gold, or silver is preferable, and copper is more preferable.
The film thickness of the metal film obtained by electroplating varies depending on the application and can be controlled by adjusting the metal concentration, immersion time, current density, etc. contained in the plating bath. From the viewpoint of properties, it is preferably 0.3 μm or more, and more preferably 1 μm or more.

<Printing device>
The printing apparatus used in the conductive pattern forming method according to the present disclosure is not particularly limited, and a known gravure printing apparatus or gravure offset printing apparatus can be used. For example, a sheet-fed or rotary gravure printing machine A gravure offset printing apparatus or a gravure type coater can be suitably used.
These printing machines or coaters are: (1) base material feed section, (2) ink that is supplied to the plate and scrapes off the non-image area ink of the plate with a doctor blade, and is held in the recess (image area) It is preferable to include a patterning unit that transfers the substrate to a substrate or a blanket, (3) a drying unit, and (4) a winding unit.
Further, if there is an exposed part between (3) the drying part and (4) the take-up part, (3) in the drying part, the solvent contained in the plating-forming ink is dried, and the exposure part is subjected to photocuring. This is preferable in that the ink can be fixed. Furthermore, there may be a substrate surface treatment portion such as a corona treatment for ensuring adhesion between the plating formable ink and the substrate between (1) the substrate feed-out portion and (2) the patterning portion. (3) Between the drying part and (4) the winding part, there may be a laminating part for attaching another substrate.

  Hereinafter, the present disclosure will be described in detail by way of examples, but the present disclosure is not limited thereto. In this example, “part” means “part by mass” unless otherwise specified.

Example 1
<Plate making conditions>
A copper sheet having a width of 170 mm, a length of 400 mm, and a thickness of 2 mm was cut with a V-shaped diamond cutting tool having an angle of 60 °, and as shown in FIGS. 3 and 4, L (line) / S (space) = 4 μm A straight vertical concave line of / 300 μm was formed on the plane. In addition, 35 mm from 4 sides of the sheet | seat was made into the blank part which does not form a concave line. Thereafter, in order to impart surface hardness, electrochrome plating was performed (plating thickness: 1 μm).

<Printing conditions>
Printing was performed with a sheet-fed gravure printing machine using the following substrate and plating-forming ink. After printing, it was dried at 50 ° C. for 5 minutes, and then irradiated on the entire surface using a 1,500 W high-pressure mercury lamp (UVX-02516S1LP01, manufactured by Ushio Electric Co., Ltd., light intensity at 254 nm: 38 mW / cm ² ).
Base material: Toyobo Co., Ltd. Cosmo Shine A4300 (polyethylene terephthalate film, thickness 38 μm)
Plating-forming ink composition:
Polyacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight 25,000): 10 parts by mass Irgacure 2959 (manufactured by Ciba Specialty Chemicals): 0.2 parts by mass N, N'-methylenebis (acrylamide) (Wako Pure Chemical Industries, Ltd.): 3.3 parts by mass, water: 90 parts by mass

<Plating formation conditions>
<< Applying electroless plating catalyst precursor >>
The substrate obtained by the above printing was immersed in a 1% by mass aqueous solution of palladium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.), which is an electroless plating catalyst precursor, for 1 minute, and then washed with distilled water.

<< Electroless copper plating >>
Thereafter, the substrate on which the electroless plating catalyst precursor was adsorbed was immersed in an electroless plating bath having the following composition, and electroless copper plating was performed at 40 ° C. for 50 minutes. After that, after baking at 90 ° C. for 60 minutes, the conductive pattern of Example 1 was obtained.

-Composition of electroless copper plating bath-
・ Distilled water: 86 mL
-ATS Ad Copper IW-A (Okuno Pharmaceutical Co., Ltd.): 5mL
-ATS Ad Copper IW-M (Okuno Pharmaceutical Co., Ltd.): 8mL
-ATS Ad Copper IW-C (Okuno Pharmaceutical Co., Ltd.): 1mL
・ NaOH: 0.22 g
・ 2,2′-bipyridyl: 0.2mg
The pH of the electroless plating bath was 12.67.

(Example 2)
A conductive pattern was obtained in the same manner as in Example 1 except that the electroless copper plating time was 80 minutes.

(Example 3)
A conductive pattern was obtained in the same manner as in Example 1 except that the printing conditions were as follows.

<Printing conditions>
Printing was performed with a sheet-fed gravure printing machine using the following substrate and plating-forming ink. After printing, it was heated at 95 ° C. for 20 minutes.
Base material: Toyobo Co., Ltd. Cosmo Shine A4300 (polyethylene terephthalate film, thickness 38 μm)
Plating-forming ink composition:
1-vinylimidazole (manufactured by Wako Pure Chemical Industries, Ltd.): 10 parts by mass 2,2′-azobis (isobutyronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.): 0.2 parts by mass 20 parts by mass of methylolpropane trimethacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), methyl ethyl ketone (manufactured by Wako Pure Chemical Industries, Ltd.): 90 parts by mass

(Example 4)
A conductive pattern was obtained in the same manner as in Example 1 except that the electroless plating catalyst precursor was silver nitrate (manufactured by Wako Pure Chemical Industries, Ltd.).

(Example 5)
A conductive pattern was obtained in the same manner as in Example 1 except that cutting was performed with a V-shaped diamond cutting tool having an angle of 20 °.

(Example 6)
A conductive pattern was obtained in the same manner as in Example 1 except that cutting was performed with a V-shaped diamond cutting tool having an angle of 80 °.

(Example 7)
A conductive pattern was obtained in the same manner as in Example 1 except that cutting was performed using a rectangular diamond cutting tool having a width of 4 μm and controlling the insertion depth so that the aspect ratio was 5.

(Example 8)
A conductive pattern was obtained in the same manner as in Example 1 except that cutting was performed using a rectangular diamond cutting tool having a width of 3 μm and controlling the insertion depth so that the aspect ratio was 7.

Example 9
A conductive pattern was obtained in the same manner as in Example 1 except that the cutting pattern in the plate making was a straight horizontal concave line shown in FIG.

(Example 10)
A conductive pattern was obtained in the same manner as in Example 1 except that the cutting pattern in the plate making was a straight vertical and horizontal grid-like concave line shown in FIG.

(Example 11)
A conductive pattern was obtained in the same manner as in Example 1 except that the cutting pattern in the plate making was a linear oblique grid-like concave line shown in FIG.

(Example 12)
A conductive pattern was obtained in the same manner as in Example 1 except that the cutting pattern in the plate making was a curved oblique grid-like concave line shown in FIG.

(Example 13)
A conductive pattern was obtained in the same manner as in Example 1 except that the cutting pattern in the plate making was a concave line including the rectangular concave line shown in FIGS.

(Example 14)
<Plate making conditions>
A nickel-phosphorous sheet having a width of 1,000 mm, a length of 640 mm, and a thickness of 200 μm is cut with a V-shaped diamond cutting tool at an angle of 60 °, and a linear shape of L (line) / S (space) = 4 μm / 300 μm. The concave line was formed on a plane. In addition, 35 mm from 4 sides of the sheet | seat was made into the blank part which does not form a concave line. This sheet was wound around an iron roll, and the ends were welded and polished so that there was no step difference in the joint, thereby producing a roll-shaped printing plate.

<Printing conditions>
The same operation as in Example 1 was performed except that printing was performed with a rotary gravure printing press.

<Plating formation conditions>
In the same manner as in Example 1, a conductive pattern was obtained.

(Example 15)
<Plate making conditions>
Electro copper plating was performed on the surface of an iron roll having a width of 1,000 mm, an outer diameter of 200 mm, and an inner diameter of 100 mm (plating thickness: 80 μm).
On the surface, cutting was performed with a V-shaped diamond cutting tool having an angle of 60 ° to form a concave line of L (line) / S (space) = 4 μm / 300 μm in the circumferential direction (35 mm from both ends of the roll). Is a blank portion that does not form a concave line).
Thereafter, in order to impart surface hardness, electrochrome plating was performed (plating thickness: 1 μm).

<Printing conditions>
The same operation as in Example 1 was performed except that printing was performed with a rotary gravure printing press.

<Plating formation conditions>
In the same manner as in Example 1, a conductive pattern was obtained.

(Example 16)
<Plate making conditions>
Electro copper plating was performed on the surface of an iron roll having a width of 1,000 mm, an outer diameter of 200 mm, and an inner diameter of 100 mm (plating thickness: 80 μm).
On the surface, cutting was performed with a V-shaped diamond cutting tool having an angle of 60 ° to form a concave line of L (line) / S (space) = 4 μm / 300 μm in the circumferential direction (35 mm from both ends of the roll). Is a blank portion that does not form a concave line.) Thereafter, a concave line of L / S = 4 μm / 300 μm was formed in the width direction so as to form an angle of 90 ° with the concave line in the circumferential direction.
Thereafter, in order to impart surface hardness, electrochrome plating was performed (plating thickness: 1 μm).

<Printing conditions>
The same operation as in Example 1 was performed except that printing was performed with a rotary gravure printing press.

<Plating formation conditions>
In the same manner as in Example 1, a conductive pattern was obtained.

(Example 17)
The plate making conditions and printing conditions were the same as in Example 1.

<Plating formation conditions>
The substrate obtained by the above printing was immersed in a chromic acid etching solution containing 400 g / L of CrO ₃ and 400 g / L of sulfuric acid at 70 ° C. for 10 minutes. Then, after dipping in a 0.5 mol / L aqueous solution of potassium permanganate for 10 minutes at 60 ° C., it was immersed in a 0.05 mol / L aqueous solution of nickel sulfate for 2 minutes at 25 ° C., and 0.05 mol / L of dimethylamine borane as a reducing agent. It was immersed in the solution at 60 ° C. for 10 minutes. Then, electroless nickel plating was performed by immersing in an electroless nickel plating solution (Okuno Pharmaceutical Co., Ltd., TMP chemical nickel HR-T) at 50 ° C. for 10 minutes.

(Comparative Example 1)
<Plate making conditions>
Electro copper plating was performed on the surface of an iron roll having a width of 1,000 mm, an outer diameter of 200 mm, and an inner diameter of 100 mm (plating thickness: 80 μm).
On the surface, a positive photosensitive solution TSER-2104 (manufactured by Sink Laboratory Co., Ltd.) was applied at a thickness of 3.5 μm and dried at 23 ° C. for 45 minutes to form a resist layer.
Next, using a laser exposure apparatus Laser-Stream-FX-1300 (manufactured by Sink Laboratory Co., Ltd.), exposure was performed at an exposure power of 230 mJ / cm ² and a cylinder rotation speed of 200 rpm (rotation / min). In the image pattern, L (line width) is 4 μm, which is the limit of the apparatus, and L (line) / S (space) = 4 μm / 300 μm concave line (35 mm from both ends of the roll is a blank part that does not form a concave line) ).
After the exposure, rotary immersion development was performed at 25 ° C. for 80 seconds using a TLD developer (manufactured by Sink Laboratories).
After the development, the cupric chloride aqueous solution was sprayed with a spray etching apparatus, and the copper was etched at 37 ° C. so that the etching depth was about 3.5 μm, which is substantially the same as that in Example 1. Then, after washing with water and drying, the resist layer in the unexposed area was peeled off to obtain a roll whose entire surface was copper.
Thereafter, in order to impart surface hardness, electrochrome plating was performed (plating thickness 1 μm) to obtain a printing plate.

<Printing conditions>
The same operation as in Example 1 was performed except that printing was performed with a rotary gravure printing press.

<Plating formation conditions>
In the same manner as in Example 1, a conductive pattern was obtained.

(Comparative Example 2)
<Plate making conditions>
A resist composition was prepared as follows.
After mixing 40 parts of nitrocellulose varnish, 10 parts of carbon black (Raven 780 Ultra Powder manufactured by Columbian Chemical Co., Ltd.) and 5 parts of ethyl acetate with a disper, they were kneaded with an Eiger mill to prepare a mill base. To this was added 6 parts of a polyester resin varnish, 4 parts of castor oil as a plasticizer, and 35 parts of ethyl acetate / toluene / isopropyl alcohol (mixing ratio: 40/40/20) as a diluent solvent to obtain a resist composition.
In the resist composition, Zahn Cup No. 3 was added for 15 seconds to obtain a coating solution.
Electro copper plating was performed on the surface of an iron roll having a width of 1,000 mm, an outer diameter of 200 mm, and an inner diameter of 100 mm (plating thickness: 80 μm).
The coating solution was applied to the surface and dried at 23 ° C. for 45 minutes. The resist film thickness after drying was 3 μm.

Subsequently, the resist layer was ablated by irradiating with a Nd: YAG laser having a wavelength of 1064 nm using a laser exposure apparatus Digilas (manufactured by Schepers). In the image pattern, L (line width) is 4 μm, which is the limit of the apparatus, and L (line) / S (space) = 4 μm / 300 μm concave line (35 mm from both ends of the roll is a blank part that does not form a concave line) .)
After the exposure, an aqueous cupric chloride solution was sprayed with a spray etching apparatus, and the copper was etched at 37 ° C. so that the etching depth was about 3.5 μm, which is substantially the same as that in Example 1. Then, it washed with water and dried.
The resist layer of the non-ablation part was peeled off using the diluting solvent used in the preparation of the resist composition to obtain a roll whose entire surface was copper.
Thereafter, in order to impart surface hardness, electrochrome plating was performed (plating thickness 1 μm) to obtain a printing plate.

<Printing conditions>
The same operation as in Example 1 was performed except that printing was performed with a rotary gravure printing press.

<Plating formation conditions>
In the same manner as in Example 1, a conductive pattern was obtained.

(Comparative Example 3)
<Plate making conditions>
Electro copper plating was performed on the surface of an iron roll having a width of 1,000 mm, an outer diameter of 200 mm, and an inner diameter of 100 mm (plating thickness: 80 μm).
On the surface, engraving was performed with a V-shaped diamond stylus having an angle of 130 ° (engraving machine: Helio Klischograph K500, manufactured by Helgravia Japan Co., Ltd.). 35 mm from both ends of the roll was a blank portion where no image was formed.
However, even the minimum point (2% halftone dot portion) is 12 μm wide and the points are discrete, and could not be recognized as a line. Therefore, printing could not be performed and the sheet resistance value could not be measured.

(Comparative Example 4)
Using a rectangular diamond cutting tool having a width of 3 μm, the insertion depth was controlled so that the aspect ratio was 8, and cutting was performed in the same manner as in Example 1. However, as a result of observing the bite after processing, chipping (chips) was observed at the corners. Moreover, although printing and plating formation were performed similarly to Example 1, the disconnection was observed.

<Evaluation>
The confirmation of the presence or absence of disconnection, the measurement of the line width, and the measurement of the variation in the line width were performed using a 3 CCD color confocal microscope (OPTELICS manufactured by Lasertec Corporation) for the line width of the printed line on the substrate.
The line width was measured at six points in the circumferential direction to obtain an average value.
For the measurement of the variation in line width, the difference between the maximum value and the minimum value of the line width in the entire region was obtained, and the value was used as the variation.
The sheet resistance value was measured according to JIS K7194 using a resistivity meter (Lorestar GX MCP-T700 manufactured by Mitsubishi Chemical Corporation).
The transmittance (light transmittance) was measured according to JIS K7361-1 using a haze meter (NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd.).
Table 1 shows the measurement results of the line width and depth of the concave line and the aspect ratio (depth / line width).
The evaluation results are shown in Table 2.

  As shown in Table 2, it can be seen that in Examples 1 to 17, a low-resistance conductive pattern having a small line width, few disconnections, and excellent light transmittance can be formed.

  10: concave line, 12: metal layer, 14: depth of concave line, 16: line width of concave line, 100: printing plate, 102: metal plate, 104: cutting part, 106: concave line, 108: FIG. ~ Schematic enlarged portion in FIG. 8, 108A: schematic enlarged portion in FIG. 10, 108B: schematic enlarged portion in FIG.

Claims (10)

Preparing a printing plate having a concave line on its surface;
A step of holding a plating-forming ink in the concave portion of the concave line,
Transferring the plating-formable ink held in the recess to the substrate; and
Forming a plating on the plating-formable ink transferred to the substrate;
The line width of the concave line is less than 20 μm,
The conductive pattern forming method, wherein an aspect ratio which is a value obtained from the depth of the concave line / the line width of the concave line is more than 0.5 and 7 or less.   The conductive pattern forming method according to claim 1, wherein the concave line is a concave line formed by cutting.   The conductive pattern forming method according to claim 1, wherein the plating-formable ink includes a compound having a functional group that interacts with an electroless plating catalyst or a precursor thereof.   The conductive pattern forming method according to claim 3, wherein the electroless plating catalyst is an electroless copper plating catalyst.   The conductive pattern forming method according to claim 1, wherein the concave line is a concave line formed by cutting using a cutting tool.   The conductive pattern forming method according to claim 5, wherein the cutting tool does not vibrate at a constant frequency in a direction perpendicular to a surface to be cut of the printing plate during cutting.   The said printing plate is a metal plate, The conductive pattern formation method of any one of Claims 1-6.   The conductive pattern forming method according to claim 7, wherein the metal plate is a metal roll.   The conductive pattern forming method according to claim 1, wherein the concave line includes a concave line having a line width of 10 μm or less.   The conductive pattern forming method according to claim 1, wherein the aspect ratio is more than 1.0 and 7 or less.