JP6073603B2 - Substrate manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a substrate having a predetermined conductive pattern.

  Printable electronics is a technique for manufacturing an electronic device using printing, and the manufacturing process is greatly simplified compared to a conventional method of individually depositing materials such as semiconductors, metals, and insulators. Applications are expected to be applied to a wide range of fields such as organic EL displays, solar cells, electronic paper, and flexible substrates. These include various elements exhibiting conductivity such as electrodes, wiring, or electromagnetic wave shielding films. For the formation of such conductive elements, one of the most frequently applied methods is to print a conductive ink containing metal particles on a substrate, and then to fire the conductive ink. Is a method of forming a wiring, a thin film and the like constituting the substrate on a substrate.

  As one of the above methods, a proposal as in Patent Document 1 has been made. In this method, by energizing the metal thin film formed on the substrate, the energized part is heated and the electric resistance value of the part is reduced. This makes it possible to reduce the electrical resistance value of the thin film portion with little damage to the substrate.

JP 2005-209907 A

  However, in the method described in Patent Document 1, the electrical resistance value of the thin film portion is not sufficiently reduced, and the degree of reduction in the electrical resistance value varies, and the electrical resistance value cannot be reliably reduced.

  The present invention solves the above-described problems, and provides a method for stably manufacturing a substrate having a sufficiently reduced resistance value.

The present invention is a method for producing a substrate having a predetermined conductive pattern, comprising a conductive ink containing a solvent containing at least one of water and an organic solvent, metal particles, and an insulating polymer. While transporting the scale-shaped base material from the unwinding roll by unwinding roll-to-roll, while applying a tension to the base material being transported by the roll-to-roll, applying step to the predetermined region of the base material The pair of energizing rolls are brought into contact with the base material during conveyance of the base material, and the first potential is applied to the first energizing roll of the pair of energizing rolls, and the second energizing roll is subjected to the second operation. By applying a potential of, a pattern forming step of energizing a predetermined region of the base material, generating heat in the predetermined region of the base material, fusing the metal particles, and forming a conductive pattern, After the pattern formation step, the base material And a step of winding said winding roll, there is provided a method of manufacturing a substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing stably the board | substrate with which resistance value was fully reduced can be provided.

It is a schematic diagram which shows the manufacturing method of the board | substrate which concerns on embodiment. It is a detailed schematic diagram of the pattern formation apparatus using the heating electricity supply roll which concerns on embodiment. It is a schematic diagram which shows the tension | tensile_strength applied at the time of manufacture of the board | substrate which concerns on embodiment. It is a schematic diagram which shows the 1st modification of the pattern formation apparatus shown in FIG. It is a schematic diagram which shows the 2nd modification of the pattern formation apparatus shown in FIG. It is a schematic diagram which shows the 3rd modification of the pattern formation apparatus shown in FIG. It is a schematic diagram which shows the 4th modification of the pattern formation apparatus shown in FIG. It is a schematic diagram which shows the modification of the application | coating process shown in FIG. It is a SEM photograph figure of the substrate surface obtained by experiment number 6.

  Embodiments of the present invention will be described below.

<Board>
In this embodiment, the substrate is a conductive ink containing a solvent containing at least one of water and an organic solvent, a metal particle, and an insulating polymer, applied to a predetermined region of the base material, It is a substrate having a conductive pattern by energizing the region while applying tension to the base material, generating heat in the region, and fusing the metal particles together.

  The board | substrate which has a conductive pattern is used for electronic devices, such as an organic EL display, a solar cell, electronic paper, a flexible substrate, for example.

<Base material>
In the present embodiment, as the base material used for forming the substrate, an inorganic base material such as glass and various plastic base materials can be used depending on the purpose of use.

  Examples of plastic substrates include polyimide, polyamideimide, polyester, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polymethyl methacrylate, polycarbonate, polyethylene naphthalate, etc. Examples thereof include a plastic synthetic polymer resin. From the viewpoint of heat resistance, mechanical properties, thermal properties, etc., it is preferable to use polyimide, polyamideimide, or polyester.

  Moreover, as a shape of a base material, a flat plate, a solid thing, a film, etc. are mentioned, A film-like thing is used suitably. By using a resin film made of the above synthetic polymer resin, it is possible to manufacture in a roll-to-roll system and to produce with high manufacturing efficiency.

  These substrates are preferably cleaned on the application surface using pure water or ultrasonic waves before applying the conductive ink.

<Conductive ink>
In the present embodiment, the conductive ink contains a solvent containing at least one of water and an organic solvent, metal particles having conductivity, and an insulating polymer.

  The conductive ink is a liquid in which conductive metal particles and an insulating polymer are dispersed in a solvent containing at least one of water and an organic solvent.

  The conductive ink is applied onto a substrate by, for example, an ink jet method or a screen printing method, dried, and then energized while applying tension to form a conductive member such as a metal particle-containing wiring or a thin film.

  The conductive ink includes metal particles (A), an insulating polymer (B), and a solvent (C) containing at least one of water and an organic solvent, and the conductive ink The ratio (A / B / C) of the metal particles (A), the insulating polymer (B) and the solvent (C) is 10% by weight to 94% by weight / 1% by weight to 10% by weight / 5% by weight. It is blended so as to be 80% by mass (a total of 100% by mass is 100% by mass).

  In the present embodiment, the conductive ink may be in the form of an emulsion or a suspension, and the solvent used may be any commonly used solvent.

  In the present embodiment, the conductive ink applied to the substrate may be a conductive paste or a metal paste. Further, as the conductive ink, for example, metal particle-containing ink and metal nanoparticle-containing ink can be used. In particular, a copper particle-containing ink and a copper nanoparticle-containing ink can be suitably used.

[Metal particles]
The metal particles contained in the conductive ink of this embodiment are copper, silver, gold, nickel, cobalt, iron, zinc, tin, aluminum, bismuth, platinum, rhodium, palladium, ruthenium, rhodium, manganese, chromium, vanadium. And titanium may be appropriately selected according to the purpose and application.
Of the above metal particles, gold, silver and copper are preferable in terms of excellent conductivity, and copper particles are particularly preferable in that there are fewer problems of migration than silver and the material cost can be suppressed.

  For example, a polyol method or a disproportionation reaction method is used as a method for producing metal particles in the present embodiment.

  The metal particles are preferably metal nanoparticles having an average particle diameter of 1 nm or more and 500 nm or less, more preferably metal nanoparticles of 1 nm or more and 300 nm or less, and particularly preferably from the viewpoint of forming a fine wiring pattern. 1 to 100 nm metal nanoparticles.

  In particular, when the metal nanoparticles are copper nanoparticles, a fine wiring pattern can be formed, and the resistance value can be stably reduced.

  The “average particle diameter” of the metal particles in the present embodiment means the particle diameter at an integrated value of 50% in the particle size distribution obtained by measuring the constant direction connection diameter. The particle size distribution can be obtained by measuring about 300 randomly from the SEM image.

  Furthermore, the copper particles or the copper nanoparticles may contain a halogen element in order to suppress their aggregation. Any halogen element may be used as long as it ionizes such as fluorine, chlorine, bromine and iodine. The halogen ion source used is dissolved in a solvent containing at least one of water and an organic solvent such as sodium chloride (hereinafter also referred to as “reaction solution”), and in the form of ions in the solution. Any substance may be used as long as it can be dispersed in the liquid. The halogen ion concentration in the reaction solution is preferably 0.04 mmol / L or more, more preferably 0.4 mmol / L or more.

[Insulating polymer]
In the present embodiment, the conductive ink contains an insulating polymer. This insulating polymer functions as a binder for metal particles.

  The conductive ink is prepared using a metal particle dispersion. The insulating polymer may be included in the metal particle dispersion to have a function of a dispersant that prevents aggregation of the metal particles. In this case, it is sufficient that at least a part of the surface of the metal particle is covered with the insulating polymer.

  The insulating polymer preferably has solubility in a solvent containing at least one of water and an organic solvent. This is preferable because it is easy to uniformly disperse together with the metal particles in the solvent when the ink is formed as a binder.

  The presence form of the insulating polymer in the conductive ink may be dissolved in a solvent, or may be an emulsion or a suspension. As the insulating polymer, for example, hydrophobic urethane, vinyl chloride, polyamide, polyester, and the like can be used, but a water-soluble polymer having high affinity with metal is preferably used.

  Examples of the water-soluble polymer in the present embodiment include celluloses such as carboxymethyl cellulose and hydroxyethyl cellulose, polysaccharides such as dextrin, starch, alginic acid, and chitosan, various natural rubbers such as gum arabic, albumin, globulin, and prolamin. In addition to simple proteins, various proteins such as gelatin, albmose, peptone, nucleoprotein, glycoprotein, or derivatives thereof, vinyl-based synthetic polymers such as polyvinylpyrrolidone, polyvinyl alcohol, and polyvinylamine and their derivatives, polyethylene glycol, polypropylene glycol And polyethers thereof and derivatives thereof. The water-soluble polymer according to this embodiment is preferably used in combination of one or more components selected from the group consisting of natural polymers and derivatives thereof, synthetic polymers and derivatives thereof.

As the natural polymer and derivatives thereof in this embodiment, it is preferable to use a combination of one or more of alginic acid and derivatives thereof, starch and derivatives thereof, and chitosan and derivatives thereof.
Moreover, as a synthetic polymer and its derivative in this embodiment, it is preferable to use combining 1 or more types from polyvinylpyrrolidone and its derivative, polyvinyl alcohol and its derivative, and polyethyleneglycol and its derivative, for example. Particularly preferred are polyvinylpyrrolidone and its derivatives, which have a high affinity for copper.

[Organic solvent]
The organic solvent in this embodiment may be either a hydrophobic solvent or a hydrophilic solvent, but a hydrophilic solvent can be preferably used.

  Any hydrophobic solvent may be used as long as it is generally used for ink or the like. For example, mineral oil, fatty acid, alcohol, hydrocarbon and the like can be mentioned.

  Examples of the hydrophilic solvent include alkanediols such as ethylene glycol and propylene glycol, polyhydric alcohols such as glycerin, sugar alcohols, lower alcohols such as ethanol, methanol, and propanol, ethylene glycol monomethyl ether, and ethylene glycol monoethyl. Examples include glycol ethers such as ether, aliphatic amines such as methylamine and triethylamine, alkanolamines such as ethanolamine and triethanolamine, and amides such as N-methylacetamide and N-methylformamide. As the hydrophilic solvent in the present embodiment, one or more of these are used in combination. Further, as the hydrophilic solvent, alcohols are preferably used, and lower alcohols such as methanol and ethanol having low molecular weight and compatibility with water-soluble substances due to their affinity with water are preferably used. preferable.

<Substrate manufacturing method>
In this embodiment, a roll-to-roll method is applied. The roll-to-roll method refers to a processing method in which the roll is unwound from the unwind roll and subjected to predetermined processing, and then wound around the take-up roll again. In the roll-to-roll method, the manufacturing apparatuses are connected to each other, and the substrate is continuously transported between the apparatuses, so that labor and the like associated with the transportation can be greatly reduced. In addition, automation of the production line is facilitated, and substrates and the like can be produced with high production efficiency.

  The substrate manufacturing method according to the present embodiment includes a coating step in which conductive ink is applied to a predetermined region of a base material, and energizing the region while applying tension to the base material to generate heat in the region, thereby generating metal particles. A pattern forming step of fusing together to form a conductive pattern. Thereby, the resistance value of the substrate is sufficiently reduced, and the substrate is stably manufactured.

  The step of unwinding the long base material from an unwinding roll, carrying out the coating step and the pattern forming step while transporting the base material by roll-to-roll, and then winding the base material around a winding roll In the coating step, the base material is unwound from an unwinding roll, and the conductive ink is applied to a predetermined region of the base material. In the pattern forming step, the tension is applied to the base material being conveyed. In addition, the region is energized, the region is heated, the metal particles are fused together, the conductive pattern is formed, and after the pattern forming step, the substrate is applied to the take-up roll. A step of winding.

  In the pattern forming step, the pair of energizing rolls contacts the base material during conveyance of the base material, and the first potential is applied to the first energizing roll of the pair of energizing rolls, and the second By applying a second potential to the energizing roll, the region is energized, the region is heated, the metal particles are fused together, and the conductive pattern is formed.

  The pair of energizing rolls are in surface contact with the substrate. In the pattern forming step, the region is energized while applying tension to the substrate while further heating the substrate. Or it has the process of heating the said base material before the said pattern formation process, and the said pattern formation process is performed using the said heated base material. The pattern formation step is performed under an inert gas or a reducing gas.

  The substrate of this embodiment is specifically manufactured as follows. This will be described in detail with reference to FIGS. 1 to 8 are schematic cross-sectional views viewed from the roll axis direction. And in description of drawing, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  FIG. 1 is a schematic diagram showing a method for manufacturing a substrate according to the present embodiment. A pair of rolls 21 and 22 disposed before and after the conveyance path of the substrate 11, an inkjet head 41, a stage 42, a temperature-controllable drying furnace 51, and a pattern forming apparatus installed between the rolls. 31, and the surface of the manufactured substrate is protected by a release sheet 61.

  The long substrate 11 is unwound from the unwinding roll 21 in the direction of the right arrow in FIG. 1, and the inkjet head 41 having a plurality of fine nozzles is moved relative to the substrate 11. 1 is applied to a predetermined region by discharging conductive ink onto the substrate 11 on the stage 42 in the direction of the downward arrow in FIG.

  In order to remove an unnecessary solvent in the conductive ink applied to the substrate 11, it is passed through a drying furnace 51 and dried. The dried substrate 11 is conveyed to the pattern forming apparatus 31.

  FIG. 2 is a detailed schematic diagram of the pattern forming apparatus 31 using the heating and energizing roll of the present embodiment. The pattern forming apparatus 31 is covered with an atmosphere control cover 16, and the inert gas or reducing gas is introduced into the pattern forming apparatus 31 from the inert gas or reducing gas inlet 17 in the downward arrow direction in FIG. Is introduced. In the pattern forming apparatus 31, the inert gas or the reducing gas is discharged from the inlet and the outlet of the base material 11. The introduction and discharge of the inert gas or reducing gas are repeated, and the pattern forming apparatus 31 is filled with the inert gas or reducing gas.

  The dried substrate 11 is conveyed by the guide roll 13a, heated by the heating energization rolls 14a, 14b, and further fed by the heating energization rolls 14a, 14b, that is, the mechanical feeding direction (hereinafter referred to as MD direction). ).

  FIG. 3 is a schematic diagram showing the tension applied during the manufacture of the substrate. The arrow direction indicating the tension is the MD direction. However, in FIG. 3, only the heating energization roll 14a is shown among the pair of heating energization rolls 14a and 14b, but tension is also applied to the base material 11 on the heating energization roll 14b in the MD direction.

  A first potential and a second potential are applied to each of the heating energizing rolls 14a and 14b while applying tension to the base material 11. Dielectric breakdown of the insulating polymer contained in the conductive ink occurs, and the metal particles are fused together by the dielectric breakdown and heat generation by energization to form a conductive pattern. And it conveys with the guide roll 13b, the formed conductive pattern is protected with the release sheet 61, the base material 11 is wound up by the winding roll 22, and the manufacturing method of the board | substrate of this embodiment is implement | achieved.

The effect of this embodiment will be described. In the coating process, an inkjet method is applied, and a fine wiring pattern can be formed.
Further, since the insulating polymer contained in the conductive ink functions as a binder, when the base material 11 is dried and an unnecessary solvent in the conductive ink applied to the base material 11 is removed, metal particles are removed. And the insulating polymer are bonded to each other, and the form of the film can be maintained.
In the pattern forming step, by applying a voltage between the heating and energizing rolls 14a and 14b, dielectric breakdown of the insulating polymer contained in the conductive ink occurs, and the metal particles are generated by the dielectric breakdown and heat generated by energization. They can be fused together. When the substrate 11 is energized while applying tension and then released from the tension, it is considered that the metal particles aggregate to form a metal thin film with few gaps between the metal particles. As a result, it is possible to stably obtain a substrate in which the resistance value is not varied and the resistance value is sufficiently reduced. Furthermore, when a tension is applied while the base material 11 is heated and energized, a substrate having a sufficiently reduced resistance value can be obtained more stably.

  Dielectric breakdown refers to a structural change in which charge carriers rapidly increase in the insulator to become a conductor when a high voltage is applied to the insulator having few charge carriers that can move freely. When a voltage is applied to the insulating polymer, a current flows to generate heat (Joule heat), and when the heat exceeds heat dissipation, the temperature in the insulating polymer rises, and the polymer structure changes and breaks.

  Here, the coating amount for applying the conductive ink to the substrate may be appropriately adjusted according to the desired film thickness in a predetermined region. In the ink jet method, the film thickness of the conductive ink after drying is 0.01. The range of 10 μm to 10 μm is preferable, and the range of 0.1 to 10 μm is particularly preferable. In the screen printing method, since the film thickness can be easily increased as compared with the inkjet method, the thickness of the conductive ink after drying is preferably in the range of 0.1 to 100 μm, particularly preferably in the range of 1 to 50 μm. That's fine.

  Alternatively, the conductive film may be formed by printing conductive ink on a base material. In this case, the conductive film can be continuously formed by the roll-to-roll method.

The drying in the drying furnace 51 may be performed at an arbitrary temperature and time in consideration of the thermal deformation and modification of the base material, the boiling point of the solvent, and the like.
The heating of the base material 11 in the pattern forming step may be performed at an arbitrary temperature in consideration of thermal deformation and modification of the base material. Moreover, it has the process of heating a base material before a pattern formation process, A pattern formation process can also be performed using the heated base material. When performing a pattern formation process using the heated base material, it may be energized by applying tension while further heating the base material.

  The pattern forming step is performed under an inert gas or a reducing gas in order to prevent oxidation of the metal particles. Examples of the inert gas include rare gas and nitrogen gas, and examples of the rare gas include helium gas and argon gas. Examples of the reducing gas include hydrogen gas and ammonia gas.

  In the present embodiment, the tension is applied to the base material 11 by appropriately setting the degree of tension. Moreover, tension can be applied to the base material 11 by making the winding speed of the base material 11 faster than the unwinding speed.

  The tension applied to the base material 11 is also adjusted appropriately depending on the type and thickness of the base material. For example, when the base material 11 is a polyimide film and the average thickness is 3 to 200 μm, the tensile force in the MD direction is 100 N / m to 400 N / from the point of suppressing distortion of the film and sufficiently reducing the resistance value. m is preferred. The tension can be measured using, for example, a load cell type sensor.

  In the pattern formation process, when the heating and energizing rolls 14a and 14b are in surface contact with the substrate 11 as shown in FIG. 2, the contact area between the heating and energizing rolls 14a and 14b and the substrate 11 is large, and the energization is efficient. Can be done.

  The form in which the heating and energizing rolls 14a and 14b are in surface contact with the substrate 11 is not limited to FIG. Any number of heating and energizing rolls and guide rolls may be used, and these rolls may be arranged in any form.

  Energization can be performed by applying a predetermined voltage to a predetermined region. Further, it can be performed by electrical conduction to a predetermined region, and can also be performed by electrically connecting the predetermined region. For energization, a DC voltage may be applied, or an AC voltage may be applied using a transformer.

  The heat generation temperature due to energization may be applied by appropriately adjusting the voltage and current to be applied so that the base material does not undergo thermal deformation and modification and the conductive pattern is formed. It is also possible to energize a predetermined region and locally heat this region to a temperature equal to or higher than the melting point of the metal particles.

  In the present embodiment, the metal particles may be fused to each other by energization heating (joule heating) in a predetermined region. That is, the fusion may melt the metal particles and bond (bond) the metal particles together. In the above fusion, spherical metal particles may be deformed by heat, and the metal particles may be brought into surface contact and bonded.

  The substrate manufacturing method according to the present invention is not limited to the above embodiment, and various modifications are possible.

  FIG. 4 is a schematic diagram showing a first modification of the pattern forming apparatus 31 shown in FIG. The dried substrate 11 is preheated using the heater 18 in the pattern forming apparatus 31, and then is conveyed by the guide roll 13a and energized while applying tension by the pair of energizing rolls 19a and 19b. When preheating is performed, a substrate having a sufficiently reduced resistance value can be obtained more stably. Further, by using the heater 18 and heating the substrate 11 without contacting the heater, the ink application surface 12 is less damaged.

  FIG. 5 is a schematic diagram showing a second modification of the pattern forming apparatus 31 shown in FIG. The dried base material 11 is conveyed using the guide roll 13a and the heating roll 20 that rotate synchronously while being preheated. By so doing, preheating can be performed in a smaller space than the heater 18 of FIG.

  FIG. 6 is a schematic diagram showing a third modification of the pattern forming apparatus 31 shown in FIG. FIG. 4 is an example in which a pair of energizing rolls 19a and 19b is applied in the pattern forming process, whereas FIG. 6 is an example in which a pair of rolls rotating in synchronization is applied. A pair of rolls that rotate in synchronism are arranged at two locations, and among these pairs of rolls, the rolls that contact the ink application surface 12 are the energizing rolls 19c and 19d, and the rolls that contact the substrate side are the guide rolls 13c 13d. At this time, the current-carrying rolls 19 c and 19 d are in line contact with the base material 11. Thereby, the base material 11 can be conveyed continuously, it can supply with electricity, applying a tension | tensile_strength to the base material 11 in conveyance, and a conductive pattern can be formed.

  FIG. 7 is a schematic diagram showing a fourth modification of the pattern forming apparatus 31 shown in FIG. FIG. 5 shows an example in which a pair of energizing rolls 19a and 19b are applied while being preheated by a guide roll 13a and a heating roll 20 that rotate synchronously, and FIG. This is an example in which electricity is applied by applying a pair of rolls that are conveyed while being preheated and that rotate in synchronization.

  FIG. 8 is a schematic diagram showing a modification of the coating process shown in FIG. FIG. 1 shows an example in which the inkjet method is applied in the coating process, while FIG. 8 shows an example in which the screen printing method is applied. Conductive ink is supplied to the substrate 11 using a mask 45 having openings of a predetermined pattern. The mask 45 is fixed to the plate frame 44 while being pulled, and the mask 45 is disposed in a predetermined region on the substrate 11, and an appropriate amount of conductive ink is supplied onto the mask 45. Next, the conductive ink can be applied to the substrate 11 by moving the squeegee device 43 while pressing the squeegee device 43 against the mask 45 supplied with the conductive ink. After applying the conductive ink, the mask 45 is removed from the base material 11 to form a conductive pattern.

  In this embodiment, the inkjet method and the screen printing method are applied as a method for applying the conductive ink to the base material. In addition, for example, a dip coating method, a spray coating method, a spin coating method, a coating method using a dispenser, etc. Is mentioned. In particular, an inkjet method or a screen printing method is preferable for forming a fine wiring pattern.

  In this embodiment, the drying furnace is applied as a method for removing unnecessary solvents in the conductive ink. However, a method for heating the outer peripheral surface of the roll can also be used.

  A method of energizing the substrate 11 while applying tension is not limited to FIGS. Any number of guide rolls, heating and energizing rolls, and energizing rolls may be used, and they may be arranged in any form. In addition, by gripping both ends in the MD direction with a grip grip and applying tension in the MD direction, a plurality of electrodes are connected to both ends of a predetermined region coated with conductive ink, and a voltage is applied to energize. You can also

  In addition, after applying conductive ink to the substrate, the surface roughness of the guide roll, heated energizing roll or energizing roll, substrate conveying speed, etc. so that the ink application surface is not damaged by friction etc. during conveyance of the substrate May be adjusted as appropriate.

  When using a conductive material as the base material, after applying the conductive ink to the base material, make sure that the guide roll, heated energizing roll or energizing roll contacts only the base material side so as not to damage the ink application surface. In addition, a roll can be provided.

Furthermore, in this embodiment, the roll-to-roll method is applied as a method for conveying the substrate, but a single wafer method may be used.
In the case of a single wafer method in which substrates are manufactured one by one, for example, both ends of the base material in the MD direction are gripped by gripping grips, and tension is applied in the MD direction while applying a predetermined region to which conductive ink is applied. A plurality of electrodes can be connected to both ends, and a DC voltage can be applied for energization.
Hereinafter, examples of the reference form will be added.
<1>
A method of manufacturing a substrate having a predetermined conductive pattern,
An application step of applying a conductive ink containing water, a solvent containing at least one of organic solvents, metal particles, and an insulating polymer to a predetermined region of the substrate;
Applying a current to the region while applying tension to the base material, generating heat in the region, fusing the metal particles together, and forming a conductive pattern; and
Having
A method for manufacturing a substrate.
<2>
<1> A method for producing a substrate according to
The step of unwinding the long base material from an unwinding roll, carrying out the coating step and the pattern forming step while transporting the base material by roll-to-roll, and then winding the base material on a winding roll Have
In the application step, the base material is unwound from the unwinding roll, the conductive ink is applied to a predetermined region of the base material,
In the pattern forming step, while applying tension to the substrate being transported, the region is energized, the region is heated, the metal particles are fused together, and the conductive pattern is formed.
Furthermore, after the pattern forming step, the step of winding the substrate around the winding roll,
A method for manufacturing a substrate.
<3>
<2> In the manufacturing method of the board | substrate of description,
In the pattern forming step, a pair of energizing rolls comes into contact with the substrate during conveyance of the substrate, and a first potential is applied to a first energizing roll of the pair of energizing rolls, and a second By applying a second potential to the energizing roll, the region is energized, the region is heated, the metal particles are fused together, and the conductive pattern is formed.
A method for manufacturing a substrate.
<4>
In the method for manufacturing a substrate according to <3>,
The pair of energizing rolls are in surface contact with the substrate;
A method for manufacturing a substrate.
<5>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <4>,
In the pattern forming step, while further heating the substrate, the region is energized while applying tension to the substrate.
A method for manufacturing a substrate.
<6>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <4>,
Before the pattern forming step, the step of heating the substrate,
The pattern forming step is performed using the heated base material.
A method for manufacturing a substrate.
<7>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <6>,
The pattern forming step is performed under an inert gas or a reducing gas.
A method for manufacturing a substrate.
<8>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <7>,
The method for producing a substrate, wherein the substrate is a resin film.
<9>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <8>,
The metal particles are metal nanoparticles having an average particle diameter of 1 nm to 500 nm.
A method for manufacturing a substrate.
<10>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <9>,
The manufacturing method of a board | substrate whose said metal particle is a copper particle.
<11>
In the manufacturing method of the board | substrate as described in <10>,
A method for manufacturing a substrate, wherein the copper particles contain a halogen element.
<12>
<1> thru | or the manufacturing method of the board | substrate as described in any one of <11>,
A method for producing a substrate, wherein the insulating polymer is a water-soluble polymer.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.

  In the following examples, cuprous oxide powder (manufactured by Kanto Chemical Co., Inc., copper (I), 3N, average particle size 1 μm) is used as a metal raw material, and concentrated sulfuric acid having a concentration of 96% (Kanto Chemical Co., Ltd.) Company use, sulfuric acid special grade), sodium ion as the halogen ion source (made by Wako Pure Chemical Industries, Ltd., reagent special grade), and polyvinylpyrrolidone K25 (Wako Pure Chemical Industries, Ltd.) as the insulating polymer. ), Wako Special Grade), and distilled water was used as the solvent.

[Example 1]
(1) Preparation of conductive ink According to the method for preparing a conductive ink described in Example 1 of JP2012-138349A, the following procedure was used.
First, copper fine particles whose surface was partially covered with a water-soluble polymer (functioning as a binder and also functioning as a dispersant) were prepared by the following procedure. 10 ml of an aqueous copper acetate solution in which 0.2 g of copper acetate ((CH ₃ COO) ₂ Cu · 1H ₂ O) was dissolved in 10 ml of distilled water as a raw material for copper fine particles, and 5.0 mol / liter (L) as a metal ion reducing agent 100 ml of an aqueous sodium borohydride solution in which sodium borohydride and distilled water were mixed so that Thereafter, 0.5 g of polyvinyl pyrrolidone (PVP, number average molecular weight of about 3500) as a water-soluble polymer was added to the aqueous solution of sodium borohydride and dissolved by stirring, and then the aqueous solution of copper acetate was added in a nitrogen gas atmosphere. 10 ml was added dropwise.

  As a result of reacting this mixed liquid with sufficient stirring for about 60 minutes, a fine particle dispersion in which copper fine particles having an average primary particle diameter of 5 to 10 nm were dispersed in an aqueous solution was obtained. Next, 5 ml of chloroform as an aggregation accelerator was added to 100 ml of the dispersion liquid in which the copper fine particles obtained by the above method were dispersed, and stirred well. After stirring for several minutes, the reaction solution was put into a centrifuge, and copper fine particles were collected by precipitation. Thereafter, the obtained copper fine particles and 30 ml of distilled water are put into a test tube, and after thoroughly stirring using an ultrasonic homogenizer, water washing for recovering the copper fine particle components with a centrifuge is performed three times, and then the same. In a test tube, the obtained copper fine particles and 30 ml of 1-butanol were added and stirred well, and then alcohol washing for recovering the copper fine particles with a centrifuge was performed three times. The copper fine particles recovered by the above steps are dispersed in 10 ml of a mixed organic solvent composed of 60% by volume of N-methylacetamide, 2% by volume of triethylamine, 10% by volume of 1-propanol, and 28% by volume of ethylene glycol as a mixed organic solvent. A conductive ink prepared by applying ultrasonic vibration in the dispersion using an ultrasonic homogenizer for 1 hour was prepared.

  When the copper fine particles in the obtained conductive ink were observed with a scanning electron microscope (hereinafter referred to as SEM, manufactured by Hitachi, Ltd., FE-SEM S-4700), the average particle diameter of the copper fine particles was as follows. It was 9 nm. The particle size of the copper fine particles was measured by randomly selecting about 300 particles from the field of view in SEM observation (imaging magnification: 250,000 times).

(2) Coating process The conductive ink prepared in the above (1) is discharged from an inkjet head with a nozzle opening of 50 μm at 1 kHz to 50 kHz on a polyimide film as a substrate, and each line has a line width of 5000 μm and 500 μm. Each was applied to the substrate. The line length was 6 cm.

(3) Drying Step In order to remove unnecessary solvent in the conductive ink applied to the substrate in (2) above, drying was performed in a drying oven at 150 ° C. for 1 hour in a nitrogen atmosphere. A copper fine particle and a water-soluble polymer were bonded to each other and the film shape was maintained.

(4) Preheating process The base material obtained by said (3) was preheated with the heater set to 170 degreeC.

(5) Pattern formation step At room temperature in a nitrogen atmosphere, both ends in the MD direction of the base material obtained in (4) above are held with a gripping grip, and a DC voltage is applied while applying a tension of 200 N / m in the MD direction. Was applied. The voltage and current at the time of application were about 3 V, 1.1 A to about 4 V, 2.0 A for the 5000 μm line, and about 3 V, 0.1 A to about 4 V, 2.0 A for the 500 μm line. Table 1 shows the results before and after the energization with a line width of 5000 μm, respectively, with experiment numbers 1 and 2 and before and after the energization with a line width of 500 μm, respectively.

[Example 2]
In Example 1, it carried out like Example 1 except having apply | coated to the base material by the screen printing method using the electroconductive ink produced in the following procedures. The experiment numbers are 5 and 6, and the results are shown in Table 1. Moreover, the SEM photograph figure of the obtained board | substrate surface (experiment number 6) is shown in FIG.
(1) Preparation of conductive ink First, 60.0 g of pure water was put into a 200 ml beaker, and stirring was started with a magnetic stirrer. To the pure water, 0.05 g (0.85 mmol) of sodium chloride, 0.3 g of propylene glycol alginate and 10.0 g of cuprous oxide were added and stirred to obtain a cuprous oxide powder slurry.
Further, 20.0 g of pure water was placed in a 100 ml beaker, and 25.0 g of concentrated sulfuric acid was added to adjust dilute sulfuric acid.
Next, at room temperature (without heating or cooling), dilute sulfuric acid was mixed for 30 seconds with the cuprous oxide powder slurry kept stirring. In addition, the addition method of dilute sulfuric acid used the method of dripping and mixing directly from a beaker. After mixing dilute sulfuric acid with the cuprous oxide powder slurry, the copper fine particles were precipitated by continuing stirring for 1 hour. When the obtained copper fine particle was observed with SEM, the average particle diameter of this copper fine particle was 270 nm. The particle size of the copper fine particles was measured by SEM observation (imaging magnification: 25,000 times).
The obtained copper fine particles were redispersed in ion-exchanged water, and then centrifuged to collect the copper fine particles. Next, the recovered copper fine particles were washed. After washing, the copper fine particles were weighed, 15% by weight of triethanolamine was added so that the copper concentration was 85% by weight, and kneaded using a mortar to obtain a conductive ink.
(2) The coating process and subsequent steps were performed in the same manner as in Example 1.

[Comparative Example 1]
In Example 1, it carried out like Example 1 except not applying tension. The experiment numbers are 7 to 10, and Table 1 shows the results.

[Evaluation method]
The resistance value was measured by a four-terminal method using a milliohm high tester 3540 manufactured by Hioki Electric Co., Ltd.
The sheet resistance (10 ⁻³ Ω) was obtained by resistance value (Ω) × line width (cm) ÷ line length (cm). The volume resistance value (μΩ · cm) was obtained by sheet resistance (10 ⁻³ Ω) × line thickness (cm).

  From Experiment Nos. 1 to 6 in Table 1, by applying current while applying tension, a metal thin film with few gaps between metal particles as shown in FIG. 9 can be obtained, and the volume resistance value is sufficiently reduced before and after energization. . Moreover, the numerical value of Table 1 is an average value of n = 3, and there was no dispersion | variation in the reduction degree of volume resistance value. On the other hand, in Comparative Example 1 of Experiment Nos. 7 to 10, there were many gaps between the metal particles, and a good metal thin film could not be obtained. Moreover, the volume resistance value was not well reduced and varied.

DESCRIPTION OF SYMBOLS 11 Base material 12 Ink application surface 13a, 13b, 13c, 13d Guide roll 14a, 14b Heating energization roll 15 Power supply 16 Atmosphere control cover 17 Inert gas or reducing gas inlet 18 Heating heater 19a, 19b, 19c, 19d 20 Heating roll 21 Unwinding roll 22 Winding roll 31 Pattern forming apparatus 41 Inkjet head 42 Stage 43 Squeegee apparatus 44 Plate frame 45 Mask 51 Drying furnace 61 Release sheet

Claims (10)

A method of manufacturing a substrate having a predetermined conductive pattern,
Conductive ink containing a solvent containing at least one of water and an organic solvent, metal particles, and an insulating polymer is transported from an unwinding roll to a roll-to-roll. While applying to a predetermined region of the substrate,
While applying tension to the base material being transported by the roll-to-roll, a pair of energizing rolls are brought into contact with the base material during transport of the base material, and the first energizing roll of the pair of energizing rolls Applying a first potential and applying a second potential to the second energizing roll energizes a predetermined region of the base material to generate heat in the predetermined region of the base material, and the metal particles A pattern forming step of fusing together to form a conductive pattern;
After the pattern forming step, a step of winding the base material on a winding roll;
A method for manufacturing a substrate. In the manufacturing method of the board | substrate of Claim 1,
The pair of energizing rolls are in surface contact with the substrate;
A method for manufacturing a substrate. In the manufacturing method of the board | substrate of Claim 1 or 2,
In the pattern forming step, a tension is applied to the substrate being conveyed by the roll-to-roll while further heating the substrate.
A method for manufacturing a substrate. In the manufacturing method of the board | substrate of Claim 1 or 2,
Before the pattern forming step, the step of heating the substrate,
The pattern forming step is performed using the heated base material.
A method for manufacturing a substrate. In the manufacturing method of the board according to any one of claims 1 to 4,
The pattern forming step is performed under an inert gas or a reducing gas.
A method for manufacturing a substrate. In the manufacturing method of the board according to any one of claims 1 to 5,
The method for producing a substrate, wherein the substrate is a resin film. In the manufacturing method of the board according to any one of claims 1 to 6,
The metal particles are metal nanoparticles having an average particle diameter of 1 nm to 500 nm.
A method for manufacturing a substrate. In the manufacturing method of the board according to any one of claims 1 to 7,
The manufacturing method of a board | substrate whose said metal particle is a copper particle. In the manufacturing method of the board | substrate of Claim 8,
A method for manufacturing a substrate, wherein the copper particles contain a halogen element. In the manufacturing method of the board according to any one of claims 1 to 9,
A method for producing a substrate, wherein the insulating polymer is a water-soluble polymer.

Images