JP2017069015A - Manufacturing method of conductive circuit laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a conductive circuit laminate, which is capable of easily connecting wirings to a conductive circuit that is capable of suppressing moire.SOLUTION: Provided is a manufacturing method of a conductive circuit laminate 10 in which a conductive circuit 15 is formed on a substrate 11 and a wiring part 18 connected to the conductive circuit 15 is formed in an end part 17 of the substrate 11. The method includes, in this order: a step of forming a random network type first conductive layer 12 made of a conductive paste on the substrate 11 including an area where the conductive circuit 15 is formed and including the end part 17 of the substrate 11; a step of forming a second conductive layer 14 with a continuous pattern made of a conductive paste on the first conductive layer 12 in the end part 17 of the substrate 11; and a step of forming a wiring part 18 by simultaneously etching the first conductive layer 12 and the second conductive layer 14 through laser etching in the end part 17 of the substrate 11.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing a conductive circuit laminate in which a conductive circuit is laminated on a substrate.

  A conductive circuit formed of a conductive layer having a predetermined pattern is used for an electronic device such as a touch panel, an electric device such as a heater, and an electromagnetic wave shield. As a method of forming a conductive layer having a pattern on a non-conductive (electrically insulating) substrate, (1) an additive method in which a conductive layer is formed only on a necessary portion, and (2) on the entire surface of the substrate. A subtractive method for removing unnecessary portions of the conductive layer after forming the conductive layer, and (3) a semi-additive method using both the additive method and the subtractive method are known.

  Various etching methods belonging to dry etching, wet etching, and the like are known as methods for removing unnecessary portions of the conductive layer. In recent years, laser etching has been attracting attention because of its low cost and low environmental load (see, for example, Patent Documents 1 and 2).

JP 2014-225709 A International Publication No. 2014/13899

  When conductive circuits are used in optical applications such as touch panels, window glass electric heaters, electromagnetic wave shields, etc., when the conductive circuits form a regular pattern like a grid mesh, the pattern (moire) due to pattern interference Visually observed, often giving undesirable visual effects. For this reason, it is conceivable to use a random network structure as a conductive circuit capable of reducing moire. However, since the positional relationship between the random network-like conductive layer and the gap is also random, there is a problem that the connection between the conductive layer and the external wiring is not easy.

  This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method of the electroconductive circuit laminated body which can connect wiring easily to the electroconductive circuit which can suppress a moire. To do.

  In order to solve the above problems, the present invention provides a conductive circuit laminate in which a conductive circuit is formed on a substrate, and a wiring portion connected to the conductive circuit is formed at an end of the substrate. A method of manufacturing, comprising: forming a random network-shaped first conductive layer made of a conductive paste on a base material including a region where a conductive circuit is formed and an end of the base material; and the base material Forming a second conductive layer having a continuous pattern made of a conductive paste on the first conductive layer at the end of the first conductive layer and the second conductive layer at the end of the substrate. There is provided a method for manufacturing a conductive circuit laminate including a step of forming a wiring portion by simultaneously etching layers by laser etching in this order.

Preferably, the method further includes a step of etching the first conductive layer by laser etching in a region where the conductive circuit is formed.
The conductive paste used for forming the first conductive layer preferably contains conductive fine particles, an emulsifier, a binder, water and an organic solvent.
The first conductive layer is preferably formed in a random network by self-organization when the conductive paste is dried.

Moreover, this invention provides the manufacturing method of the touchscreen characterized by using the conductive circuit laminated body manufactured by the manufacturing method of the said conductive circuit laminated body.
Moreover, this invention provides the manufacturing method of the heater characterized by using the conductive circuit laminated body manufactured by the manufacturing method of the said conductive circuit laminated body.
Moreover, this invention provides the manufacturing method of the electromagnetic wave shield characterized by using the conductive circuit laminated body manufactured by the manufacturing method of the said conductive circuit laminated body.

  According to the present invention, moire can be reduced by a random network conductive circuit, and wiring can be easily connected to the conductive circuit.

It is a perspective view which shows an example of the process of forming a 1st conductive layer on a base material. It is a perspective view which shows an example of the process of forming a 2nd conductive layer in the edge part of a base material. It is a perspective view which shows an example of the process of forming a wiring part by an etching. It is a top view which shows an example of the electroconductive circuit laminated body of this invention. It is a top view which shows an example of the connection structure of an electroconductive circuit and a wiring part. It is the elements on larger scale of the A section of FIG. It is a perspective view which shows the conductive circuit laminated body of a comparative example.

  Hereinafter, based on a preferred embodiment, the present invention will be described with reference to the drawings. Each drawing is a schematic diagram, and the number, shape, dimension, scale, and the like of each part may be different from actual ones.

  The conductive circuit laminate 10 of this embodiment is shown in the perspective view of FIG. 3 and the plan view of FIG. The conductive circuit laminate 10 includes a base material 11, a conductive circuit 15 formed on the base material 11, and a wiring portion 18 connected to the conductive circuit 15 at an end portion 17 of the base material 11. Prepare. The conductive circuit 15 and the wiring part 18 can be provided on one side or both sides of the substrate 11. A part of the wiring part 18 may include a part penetrating both surfaces of the substrate 11.

  Examples of the base material 11 include planar base materials such as plastic films, sheets, and plates (boards). Examples of the plastic used for the substrate 11 include, but are not limited to, polyester, polycarbonate, polyamide, polyimide, polyolefin, polyvinyl chloride, and polyvinylidene chloride. A part or all of the base material 11 may be made of a material other than plastic, for example, metal, inorganic material, paper, fiber, conductor, semiconductor, insulator, and the like. In applications that require light transmission, the substrate 11 is preferably transparent or translucent. One or both surfaces of the substrate 11 can be subjected to a surface treatment such as coating or roughening.

  The conductive circuit 15 is composed of a first conductive layer 12 made of a conductive paste. When two or more conductive circuits 15 are provided on the same surface of the base material 11, electrical insulation is secured through the gap 16. Each conductive circuit 15 is preferably strip-shaped and the gap 16 is preferably linear. The wiring part 18 has a structure in which the first conductive layer 12 and the second conductive layer 14 are laminated on the base material 11. The second conductive layer 14 is made of a conductive paste.

  An example of the connection structure between the conductive circuit 15 and the wiring portion 18 at the end portion 17 of the substrate 11 is shown in FIG. FIG. 6 shows a partially enlarged view of part A in FIG. As shown in FIG. 6, the 1st conductive layer 12 which comprises the electroconductive circuit 15 is comprised from the thin wire | line 20 which consists of a random network conductor. The fine wire 20 is formed in a mesh shape by the opening 22 generated in the first conductive layer 12.

  An electrode part 19 is provided at the tip of the wiring part 18, and the electrode part 19 is connected to the conductive circuit 15. Electrical connection is ensured by connecting one or more thin wires 20 to one electrode portion 19. The electrode portion 19 is preferably in contact with the first conductive layer 12 with a dimension wider than the opening 22 included in the random network structure. As shown in FIGS. 5 and 6, a plurality of wiring portions 18 extending from the plurality of electrode portions 19 are formed in parallel at the end portion 17 of the base material 11.

  The thin wire 20 is cut by the cutting line 21 around the conductive circuit 15, and the first conductive layer 12 is removed outside the conductive circuit 15. The removal of the first conductive layer 12 is preferably performed by laser etching. In particular, the gap portion 16 provided between the conductive circuits 15 is formed by laser etching, so that the thin wire 20 can be reliably cut even if the gap width is narrow.

  The conductive paste used for forming the first conductive layer 12 (hereinafter referred to as the first conductive paste) preferably contains conductive fine particles, an emulsifier, a binder, and a solvent (water and / or organic solvent). As the conductive fine particles used in the first conductive paste, metal particles are preferable, and metal nanoparticles are more preferable. Examples of the metal particles include metals such as gold, silver, platinum, palladium, iron, cobalt, nickel, copper, and zinc, or alloys thereof. Two or more types of metal particles may be included.

  Examples of the emulsifier used in the first conductive paste include nonionic surfactants such as mono fatty acid sorbitan and mono fatty acid glycerol, and ionic surfactants such as alkylbenzene sulfonate and sodium dodecyl sulfate. One type or two or more types of emulsifiers may be used.

  Examples of the binder used for the first conductive paste include cellulose ether, cellulose ester, urea resin, urethane resin, and modified urea. The binder may be used alone or in combination of two or more.

  The first conductive paste preferably contains, as a solvent, one or more of water or a water-soluble solvent and one or more of an organic solvent that is hydrophobic or phase-separable from water. Examples of water-soluble solvents other than water include water-soluble organic solvents such as methanol, ethanol, isopropanol, ethylene glycol, glycerol, acetone, dimethylformamide, dimethylacetamide, acetonitrile, dimethyl sulfoxide, and N-methylpyrrolidone. Examples of the organic solvent that is hydrophobic or phase-separable from water include petroleum ether, hexane, heptanes, toluene, dichloromethane, chloroform, dichloroethane, trichloroethylene, nitromethane, cyclopentanone, cyclohexanone, and the like.

  The first conductive paste preferably includes at least conductive fine particles and two or more kinds of solvents having different hydrophilicity and hydrophobicity. An emulsifier, a binder, and other additives can be optionally added. When the uniformly mixed first conductive paste is applied on the substrate and then dried, the solvents having different polarities cause phase separation in the drying process, and the conductive fine particles move and aggregate in a linear shape. The solvent droplets separated from the fine particles form the openings 22, and the thin wires 20 made of the conductive fine particles are formed in a random network by self-organization.

  The conductive paste used for forming the second conductive layer 14 (hereinafter referred to as the second conductive paste) preferably contains conductive particles, a binder, and a solvent. Examples of the conductive particles used in the second conductive paste include metals such as gold, silver, platinum, palladium, iron, cobalt, nickel, copper, and zinc, alloys thereof, and nonmetallic conductors such as carbon. The conductive particles are preferably nanoparticles, and two or more types of conductive particles may be included.

  Examples of the binder used for the second conductive paste include thermoplastic resins such as polyester resin, (meth) acrylic resin, polyethylene resin, polystyrene resin, and polyamide resin, and thermosetting such as epoxy resin, amino resin, and polyimide resin. Resin. As a solvent used for the 2nd conductive paste, 1 type, or 2 or more types chosen from the above-mentioned organic solvent etc. are mentioned, for example. The second conductive paste preferably includes at least conductive particles and a binder or a solvent. Other additives can be optionally added. The second conductive paste preferably forms a substantially uniform conductive layer in which the conductor particles aggregate after application without changing the pattern, and no opening is formed.

  Next, a method for manufacturing the conductive circuit laminate 10 of this embodiment will be described. Among the following steps, the first to third steps are performed in this order, that is, the second step after the first step and the third step after the second step. This manufacturing method optionally includes other steps before the first step, between the first step and the second step, between the second step and the third step, and after the third step. be able to.

  First, as shown in FIG. 1, as shown in FIG. 1, a first conductive paste is applied on a substrate 11 including a plastic film such as polyethylene terephthalate (PET). One conductive layer 12 is formed. The method for applying the first conductive paste is not particularly limited, and examples thereof include screen printing, spin coating, and inkjet. Use of the first conductive paste capable of forming a random network-like thin line by self-organization is preferable because of excellent productivity.

  The range in which the first conductive layer 12 is formed in the first step is not limited to the entire surface on the base material 11, but at least one of the region where the conductive circuit 15 is formed and the end portion 17 of the base material 11. Part. In order to prevent the loss of the conductive circuit 15, it is preferable to form the first conductive layer 12 on the end portion 17 of the substrate 11 over the entire circumference of the conductive circuit 15. The first conductive layer 12 is preferably formed in at least a part of the region where the wiring part 18 is formed, and more preferably, the first conductive layer 12 is formed in the entire region where the wiring part 18 is formed. . In the wiring portion 18, the first conductive layer 12 and the second conductive layer 14 are overlapped in the thickness direction, whereby the reliability of electrical connection is improved.

  Next, as a second step, as shown in FIG. 2, the second conductive paste is applied on the first conductive layer 12 at the end portion 17 of the base material 11 and dried to have a continuous pattern. Two conductive layers 14 are formed. The method for applying the second conductive paste is not particularly limited, and examples thereof include screen printing and inkjet. Here, the range in which the second conductive layer 14 is formed includes a region where the conductive circuit 15 is not formed at least in the end portion 17 of the base material 11. In the region where the conductive circuit 15 is formed, the surface 13 of the first conductive layer 12 is exposed without being covered by the second conductive layer 14. However, a part of the second conductive layer 14 may be formed on the surface 13 of the first conductive layer 12 in a region where the conductive circuit 15 is formed. Moreover, as a continuous pattern, it is preferable that one pattern includes two or more wiring portions 18 and a region therebetween, and is continuous over one side, two sides, or the entire circumference of the substrate 11. Is preferred.

  Next, as a third step, as shown in FIG. 3, the first conductive layer 12 and the second conductive layer 14 are simultaneously etched by laser etching at the end portion 17 of the substrate 11. Thereby, the wiring part 18 which consists of the 1st conductive layer 12 and the 2nd conductive layer 14 can be formed. The wiring width and the wiring interval of the wiring part 18 are not particularly limited, but are, for example, about 50 μm. Similarly to the wiring part 18, the electrode part 19 shown in FIGS. 5 and 6 can be formed. However, the etching around the electrode portion 19 in the third step may be performed only on the side where the electrode portion 19 is in contact with the end portion 17 of the base material 11, and at the boundary where the electrode portion 19 is in contact with the conductive circuit 15, Etching is not required. In the second step, when the desired shape of the electrode part 19 is obtained by applying the second conductive paste, the etching around the electrode part 19 can be omitted over the entire circumference in the third step.

  In the manufacturing method of the present embodiment, a step of etching the first conductive layer 12 by laser etching in a region where the conductive circuit 15 is formed can be further provided as a fourth step. Laser etching can be used to form a gap 16 that insulates the strip-like conductive circuits 15 from each other. The fourth step can be performed in any order as long as the first conductive layer 12 is formed in the first step. In particular, it is preferable to perform the third step and the fourth step at the same time or by continuing both in front and back, since the laser etching step can be continuously performed, which is excellent in workability.

  Furthermore, as a fifth step, a step of connecting the wiring portion 18 to an external circuit such as a drive circuit (not shown) can be provided. Thereby, the conductive circuit 15 can be connected to an external circuit via the wiring part 18.

As an example, the dimension of each part in the conductive circuit laminated body 10 of this embodiment is illustrated. In addition, this invention is not limited by this illustration.
Random network structure opening: 50-500 μm
Fine wire width of random network structure: 2-20μm
Laser etching width of the gap 16: 15-30 μm
Etching pitch of conductive circuit 15: 6 mm
Wiring width of the wiring part 18: 50 μm
Wiring pitch of the wiring part 18: 50 μm
Dimension of electrode part 19: 4.8 mm × 0.5 mm

  As a comparative example, the conductive circuit laminate 100 shown in FIG. 7 includes a conductive network 15 and a wiring formed by etching the first conductive layer 12 after the first conductive layer 12 having a random network shape is formed on the substrate 11. Manufactured by a method of forming the portion 18. In the case of this manufacturing method, the wiring portion 18 is composed of random network-like thin wires, so that if the wiring width is thin, there is a possibility that the thin wires are disconnected, and in order to ensure electrical connection, there is a problem that the wiring width becomes thick. is there.

  According to the conductive circuit laminate 10 of the present embodiment, the conductive circuit 15 is formed from the random network-shaped first conductive layer 12, and the electrical connection of the wiring portion 18 is different from the first conductive layer 12. Since it is ensured by the conductive layer 14, it is possible to easily connect the wiring portion 18 having a narrow wiring width to the conductive circuit 15 capable of suppressing moire. The conductive circuit laminate 10 of the present embodiment can be suitably used as a conductive circuit such as a touch panel, a heater, and an electromagnetic wave shield. In touch panel applications, by providing a plurality of conductive circuits 15 in a strip shape with a gap 16 therebetween, the touch position determination accuracy can be improved.

  As mentioned above, although this invention has been demonstrated based on suitable embodiment, this invention is not limited to the above-mentioned embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

  In the above-described embodiment, the conductive circuit 15 is provided in the central portion of the base material 11 and the periphery (four sides) of the conductive circuit 15 is the end portion 17 on which no conductive layer other than the wiring portion 18 is provided. However, the arrangement is not limited to this. For example, one or more arbitrary sides of the substrate 11 can be the end portion 17. The planar shape of the substrate 11 is not limited to a polygonal shape (polygonal shape) such as a rectangle, but may be a desired shape such as a circular shape or an elliptical shape. The substrate 11 may be a curved surface such as a cylinder or a corrugated plate. When the substrate 11 is flexible, the conductive circuit laminate 10 can be freely deformed.

DESCRIPTION OF SYMBOLS 10 ... Conductive circuit laminated body, 11 ... Base material, 12 ... 1st conductive layer, 13 ... Surface of 1st conductive layer, 14 ... 2nd conductive layer, 15 ... Conductive circuit, 16 ... Gap part, 17 ... Group End part of material, 18 ... wiring part, 19 ... electrode part, 20 ... fine wire, 21 ... cutting line, 22 ... opening.

Claims (7)

A method for producing a conductive circuit laminate in which a conductive circuit is formed on a substrate, and a wiring portion connected to the conductive circuit is formed at an end of the substrate,
Forming a random network-shaped first conductive layer made of a conductive paste on a substrate including a region where a conductive circuit is formed and an end of the substrate;
Forming a second conductive layer having a continuous pattern made of a conductive paste on the first conductive layer at an end of the substrate;
Forming a wiring portion by simultaneously etching the first conductive layer and the second conductive layer by laser etching at an end portion of the base material;
The manufacturing method of the conductive circuit laminated body characterized by including in this order.   The method for manufacturing a conductive circuit laminate according to claim 1, further comprising a step of etching the first conductive layer by laser etching in a region where the conductive circuit is formed.   The method for producing a conductive circuit laminate according to claim 1 or 2, wherein the conductive paste used for forming the first conductive layer contains conductive fine particles, an emulsifier, a binder, water, and an organic solvent. .   4. The conductive circuit laminate according to claim 1, wherein the first conductive layer is formed in a random network by self-organization when the conductive paste is dried. 5. Manufacturing method.   The manufacturing method of the touch panel characterized by using the conductive circuit laminated body manufactured by the manufacturing method of the conductive circuit laminated body of any one of Claims 1-4.   The manufacturing method of the heater characterized by using the conductive circuit laminated body manufactured by the manufacturing method of the conductive circuit laminated body of any one of Claims 1-4.   The manufacturing method of the electromagnetic wave shield characterized by using the conductive circuit laminated body manufactured by the manufacturing method of the conductive circuit laminated body of any one of Claims 1-4.

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