JP2019140284A - Metal wiring manufacturing method, structure with metal wiring, and metal wiring manufacturing apparatus - Google Patents

Abstract

To provide a metal wiring manufacturing method, a structure with a metal wiring, and a metal wiring manufacturing apparatus, capable of easily obtaining a metal wiring having a uniform resistance value.SOLUTION: When a metal wiring (1) is manufactured, a surface including metal particles is repeatedly scanned with light to sinter the metal particles to form the metal wiring. According to lengths (L1, L2) of a scanning line (Ia) constituting the metal wiring, a scanning speed of the light beam is varied, so that scanning periods at points (A) and (B) are made substantially the same, and a resistance value of the metal wiring is made uniform.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing metal wiring, a structure with metal wiring, and a metal wiring manufacturing apparatus.

  The circuit board has a structure in which conductive wiring is provided on the board. A circuit board manufacturing method is generally as follows. First, a photoresist is applied on a substrate on which a metal foil is bonded. Next, the photoresist is exposed and developed to obtain a negative shape of a desired circuit pattern. Next, a portion of the metal foil not covered with the photoresist is removed by chemical etching to form a pattern. Thereby, a high performance conductive substrate can be manufactured.

  However, the conventional method has many drawbacks such as a large number of steps and is complicated and requires a photoresist material.

  On the other hand, direct wiring printing that directly prints a desired wiring pattern on a substrate with a dispersion in which fine particles selected from the group consisting of metal fine particles and metal oxide fine particles are dispersed (hereinafter also referred to as “paste material”). Technology is drawing attention. This technique has extremely high productivity because it requires a small number of processes and does not require the use of a photoresist material.

  As an example of direct printing wiring technology, a method is known in which a paste material is applied to the entire surface of a substrate, a laser beam is irradiated onto the paste material in a pattern and selectively heat-fired to obtain a desired wiring pattern. (For example, see Patent Documents 1 and 2).

  In Patent Document 2, when drawing is performed by irradiating a GaAlAs laser beam having a wavelength of 830 nm, the beam diameter on the copper oxide thin film is 5 μm, and the portion irradiated with the laser beam is locally heated so that the copper oxide is It is described that a reduced metal region composed of reduced copper having a width of approximately 5 μm is formed by reduction.

International Publication No. 2010/024385 JP-A-5-37126

  As described above, the width of the reduced metal region formed by drawing by laser light irradiation is almost equal to the beam diameter and is narrow. For this reason, in order to form a larger reduced metal region, it is necessary to repeatedly scan the copper oxide thin film with a laser beam to widen the region irradiated with the laser.

  For example, a galvano scanner is used to scan the laser beam, which is irradiated with one point of laser beam and moved like a single stroke, and laser is applied to a region of a desired size and shape on the surface of the copper oxide thin film. Irradiate light.

  In the circuit board, the metal wiring is required to have a uniform resistance value. When the laser light is scanned on the copper oxide thin film, if the heating condition by the laser light varies, the resistance value of the metal wiring varies. In particular, when the shape of the metal wiring is not a simple line, square, or rectangle, variation in resistance value may easily occur.

  In addition, when heating with laser light such as one-stroke writing is insufficient, reduction and sintering of copper oxide may be insufficient, and a sufficiently low resistance metal wiring may not be easily obtained.

  This invention is made in view of this point, and provides the manufacturing method of metal wiring, the structure with metal wiring, and the metal wiring manufacturing apparatus which can obtain the metal wiring of uniform resistance value easily. One of the purposes.

  As a result of intensive studies to solve the above problems, the present inventor has completed the present invention.

  That is, one aspect of the method for producing a metal wiring of the present invention comprises a step of repeatedly scanning light on a surface containing metal particles to sinter the metal particles to form the metal wiring, and configure the metal wiring. The scanning speed of the light beam is varied according to the length of the scanning line to be performed.

  With this configuration, when the shape of the metal wiring is complicated and the length of the scanning line is different, the difference in the amount of heat stored by one scan is caused by the point because the scanning speed of the light beam is constant. Therefore, the degree of sintering of the metal particles can be made uniform, and a metal wiring having a uniform resistance value can be easily obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of metal wiring, the structure with metal wiring, and the metal wiring manufacturing apparatus which can obtain the metal wiring of uniform resistance value easily can be provided.

It is a schematic diagram which shows an example of the scanning of a metal wiring and a light ray in the manufacturing method of the metal wiring which concerns on this Embodiment. It is a schematic diagram which shows the relationship between the copper oxide particle contained in the insulation area | region and the phosphate ester salt in the manufacturing method of the metal wiring which concerns on this Embodiment. It is a cross-sectional schematic diagram which shows the structure with metal wiring which concerns on this Embodiment. It is a schematic diagram which shows an example of the metal wiring manufacturing apparatus which concerns on this Embodiment. It is a schematic diagram which shows the mutually overlapping scanning line in the metal wiring manufacturing method which concerns on this Embodiment. It is explanatory drawing of the metal wiring manufacturing apparatus which concerns on this Embodiment. It is explanatory drawing of the condensing control part which concerns on this Embodiment. It is explanatory drawing which shows each process of the manufacturing method of the support body with metal wiring which concerns on this Embodiment. It is an optical microscope photograph of the surface of the electroconductive pattern in Example 1 of this invention.

  Hereinafter, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail.

<Overview>
The present inventor found that when the shape of the metal wiring is complicated and the length of the scanning line is different, the amount of heat stored by one scanning varies depending on the point due to the constant scanning speed of the light beam. Focused on that.

  FIG. 1 is a schematic diagram illustrating an example of scanning of a metal wiring and a light beam in the metal wiring manufacturing method according to the present embodiment. As shown in FIG. 1, when it is intended to obtain a metal wiring 1 having a pattern in which two rectangular regions 1a and 1b having different sizes are combined, the vertical direction on the paper is the X axis (main scanning direction) and the horizontal direction. The whole metal wiring 1 is irradiated with the light beam by scanning the light beam with the direction as the Y-axis (sub-scanning direction). In FIG. 1, a solid line I indicates that a portion irradiated with one light beam (hereinafter referred to as an irradiation point) moves on the surface of a layer to be processed (described later), so that metal particles contained in the surface are sintered. The drawn linear region is shown. A portion of the solid line I corresponding to the irradiation point moving once in the X-axis direction is referred to as a scanning line Ia. The metal wiring 1 is composed of a plurality of scanning lines Ia.

  In the pattern of the metal wiring 1 as shown in FIG. 1, there are portions where the lengths of the scanning lines Ia are different between the region 1a and the region 1b. That is, the length L1 of the scanning line Ia in the region 1a having a long length in the X-axis direction and the length L2 of the scanning line Ia in the region 1b having a short length in the X-axis direction among the metal wirings 1. In contrast, the relationship is L1> L2.

  In such a case, after the light beam passes through one point A belonging to the region 1a and one point B belonging to the region 1b by one scanning (scanning for one scanning line Ia), the next The interval until it returns to the vicinity of the points A and B by one scanning is called a scanning cycle (F). When the speed (V) for scanning the light beam is constant, the scanning period (F) varies depending on the length (L) of the scanning line Ia. Therefore, the scanning periods (F) at points A and B are different. As a result, the amount of heat stored on the surface of the layer to be processed is increased by one scan at the point B rather than the point A. That is, the amount of heat applied to the surface of the layer to be processed at point B is greater than the amount of heat applied to the surface of the layer to be processed at point A. As a result, when light is irradiated on the surface of the layer to be processed by the next one-time scanning, a difference occurs between the points A and B in the heating temperature of the surface. Therefore, there is a difference between the points A and B in the degree to which the metal particles are sintered on the surface of the layer to be processed (hereinafter referred to as the degree of sintering). As a result, the resistance value of the metal wiring 1 is different between the region 1a and the region 1b and becomes non-uniform. Further, it has been found that such a phenomenon is remarkable when the metal wiring 1 is formed so that adjacent scanning lines overlap each other. The reason for this is considered to be that the resistance value of the metal wiring 1 is likely to be different because the amount of heat storage increases when scanning is performed so that the scanning lines do not overlap.

  Therefore, the present inventor varies the sintering degree of the metal particles by varying the speed (V) of scanning the light beam according to the length (L) of the scanning line Ia constituting the metal wiring 1 (see FIG. 1). As a result, it was found that the metal wiring 1 having a uniform resistance value can be easily obtained by suppressing the occurrence of variations in the thickness, and the present invention has been completed.

  That is, the manufacturing method of the metal wiring 1 according to the present embodiment includes a step of scanning the light repeatedly on the surface including the metal particles to sinter the metal particles to form the metal wiring 1. It is characterized in that the speed (V) at which the light beam is scanned is varied according to the length of the scanning line Ia to be configured.

  In the method for manufacturing the metal wiring 1 according to the present embodiment, it is preferable to set the scanning speed (V) of the light beam so that the scanning period (F) is substantially the same.

  Further, it is preferable to form the metal wiring 1 so that the adjacent scanning lines Ia overlap each other. Thereby, the degree of sintering of the metal particles is increased by using the light emitted from the light source having the same output, and a uniform metal wiring having a sufficiently low resistance value can be easily obtained.

  Further, it is preferable that the scanning lines Ia overlap by 5% to 99% in the width direction.

  Hereinafter, as an example of the method for manufacturing the metal wiring 1 according to the present embodiment, the surface including metal particles is formed from a dispersion (copper oxide ink) including copper oxide particles and a phosphorus-containing organic substance as a dispersant. Will be described.

  FIG. 2 is a schematic diagram showing the relationship between the copper oxide particles and the phosphate ester salt in the layer to be treated in the metal wiring manufacturing method according to the present embodiment. The to-be-processed layer 11 in FIG. 2 is a layer containing the phosphate ester salt 12 which is an example of the copper oxide particle 12 and phosphorus containing organic substance, and is also called a copper oxide ink layer. As shown in FIG. 2, in the treated layer 11, around the copper oxide particles 12, the phosphate ester salt 13 surrounds the phosphorus 13 a on the inside and the ester salt 13 b on the outside. Since the phosphate ester salt 13 exhibits electrical insulation, electrical continuity between adjacent copper oxide particles 12 is hindered.

  Therefore, since the copper oxide particles 12 are semiconductors and conductive, but are covered with the phosphate ester salt 13 exhibiting electrical insulation, the layer 11 to be treated before firing (described later) has electrical insulation. It is possible to ensure insulation between metal wirings (described later) adjacent to both sides of the insulating region 11 in a sectional view (a cross section along the vertical direction shown in FIG. 2).

  On the other hand, the metal wiring 1 (see FIG. 1), for example, irradiates a part of the surface of the layer to be processed with light, and reduces the copper oxide to copper in the part of the region. Copper in which copper oxide is thus reduced is referred to as reduced copper. Further, in the partial region, the phosphorus-containing organic substance is modified into a phosphorus oxide. In the phosphor oxide, an organic substance such as the above-described ester salt 13b (see FIG. 2) is decomposed by the heat of light and does not exhibit electrical insulation.

  In addition, as shown in FIG. 2, when copper oxide particles 12 are used, the copper oxide changes into copper particles made of reduced copper and sinters by the heat of light, and adjacent copper particles are integrated with each other. To do. Thereby, the metal wiring 1 (refer FIG. 1) which has the outstanding electrical conductivity can be formed.

  In the metal wiring 1, the phosphorus element remains in the reduced copper. The phosphorus element exists as at least one of a phosphorus element simple substance, a phosphorus oxide, and a phosphorus-containing organic substance. The remaining phosphorus element is segregated in the metal wiring 1 and there is no fear that the resistance of the metal wiring 1 will increase.

<Configuration of structure with metal wiring>
FIG. 3 is a schematic cross-sectional view showing the structure with metal wiring according to the present embodiment. As shown in FIG. 3, the structure 20 with metal wiring includes a support 21, an insulating region 22 containing copper oxide and a phosphorus-containing organic substance, and copper particles on a surface formed by the support 21 in a cross-sectional view. The metal wiring 23 formed by sintering comprises a single layer 24 disposed adjacent to each other. The insulating region 22 is a region of the processing target layer 11 (see FIG. 2) that is not irradiated with light.

<Support>
The support 21 constitutes a surface on which the single layer 24 is arranged. The shape is not particularly limited.

  The material of the support 21 is preferably an insulating material in order to ensure electrical insulation between the metal wirings 23 separated by the insulating region 22. However, it is not always necessary that the entire support 21 is made of an insulating material. Only the portion constituting the surface on which the single layer 24 is disposed needs to be an insulating material.

  More specifically, the support 21 may be a flat plate, a film, or a sheet. The plate-like body is a support (also called a base material) used for a circuit board such as a printed board. The film or sheet is a base film which is a thin film insulator used for a flexible printed circuit board, for example.

  The support 21 may be a three-dimensional object. A single layer can also be arranged on a curved surface or a surface including a step formed by a three-dimensional object.

  As an example of the three-dimensional object, a casing of an electric device such as a mobile phone terminal, a smart phone, a smart glass, a television, or a personal computer can be given. Other examples of the three-dimensional object include a dashboard, an instrument panel, a handle, and a chassis in the automobile field.

<Single layer>
In the present embodiment, it can be said that the single layer 24 is a mixture of the insulating region 22 and the metal wiring 23.

  “Single” in the single layer 24 means that the layer is not a multilayer structure and that the layers are continuous in cross-sectional view. That the layers are continuous in a cross-sectional view means that it does not include a state in which, for example, a layer between the patterned wiring layers is filled with a solder paste as seen in a printed circuit board. .

  Therefore, the single single layer 24 does not mean that the whole is homogeneous, and the electrical conductivity, the particle state (fired and unsheathed) like the relationship between the insulating region 22 and the metal wiring 23. (Firing) or the like may be different, or a boundary (interface) may exist between the two.

<Insulation region>
The insulating region 22 includes copper oxide and a phosphorus-containing organic material and exhibits electrical insulation. It can be said that the insulating region 22 is an unirradiated region that has not been irradiated with light. The insulating region 22 can also be said to be an unreduced region where copper oxide is not reduced by light irradiation. The insulating region 22 can also be said to be an unfired region that has not been fired by light irradiation.

<Metal wiring>
The metal wiring 23 contains copper and exhibits electrical conductivity. It can be said that the metal wiring 23 is an irradiated region that has been irradiated by a laser. The metal wiring 23 can also be said to be a reduction region including reduced copper in which copper oxide is reduced by light irradiation. The metal wiring 23 can also be said to be a fired region including a fired body obtained by firing the insulating region 22 by light irradiation.

  The shape of the metal wiring 23 in a plan view, that is, the pattern may be any of a linear shape, a curved shape, a circular shape, a square shape, a bent shape, and the like, and is not particularly limited. Since the pattern is formed by scanning with laser light, it is difficult to be restricted by the shape.

  The boundary between the insulating region 22 and the metal wiring 23 is preferably a straight line along the thickness direction (vertical direction shown in FIG. Y) of the single layer 24 in a cross-sectional view, but may have a taper angle. There is no particular limitation. However, it is not essential that the boundary is clear.

  The metal wiring 23 does not need to be completely reduced in a sectional view. For example, it is preferable that there is an unreduced portion near the support 21. Thereby, the adhesiveness between the metal wiring 23 and the support body 21 becomes high.

<Details of structure>
Hereinafter, each structure of the structure 20 with metal wiring which concerns on this Embodiment is demonstrated concretely. However, each configuration is not limited to the specific examples given below.

(Support)
Specific examples of the support include, for example, a support made of an inorganic material (hereinafter referred to as “inorganic support”) or a support made of a resin (hereinafter referred to as “resin support”).

  The inorganic support is made of, for example, glass, silicon, mica, sapphire, crystal, clay film, and ceramic material. The ceramic material is, for example, alumina, silicon nitride, silicon carbide, zirconia, yttria and aluminum nitride, and a mixture of at least two of these. In addition, as the inorganic support, a support made of glass, sapphire, crystal, or the like that has particularly high light transmittance can be used.

  Examples of the resin support include polyimide (PI), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC), polyvinyl alcohol (PVA), and polyvinyl butyral ( PVB), polyacetal (POM), polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), modified polyphenylene ether (m-PPE), polyphenylene sulfide ( PPS), polyether ketone (PEK), polyphthalamide (PPA), polyether nitrile (PENt), polybenzimidazole (PBI), polycarbodiimide, polysiloxane, Rimethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, phenol resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA), polybutene, polypentene, ethylene-propylene copolymer, ethylene-butene -Diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), polyvinyl chloride ( PVC), polyvinylidene fluoride (PVDF), polyetheretherketone (PEEK), phenol novolac, benzocyclobutene, polyvinylphenol, polychloropyrene, polyoxymethylene, polysulfo (PSF), polyphenylsulfone resin (PPSU), cycloolefin polymer (COP), acrylonitrile / butadiene / styrene resin (ABS), acrylonitrile / styrene resin (AS), nylon resin (PA6, PA66) polybutyl terephthalate resin A support composed of (PBT) polyethersulfone resin (PESU), polytetrafluoroethylene resin (PTFE), polychlorotrifluoroethylene (PCTFE), silicone resin, and the like can be used.

  Moreover, although not distinguished above, a resin sheet containing cellulose nanofibers can also be used as a support.

  In particular, at least one selected from the group consisting of PI, PET, and PEN is excellent in adhesion with a single layer, has good market distribution and is available at low cost, and is significant from a business perspective, preferable.

  Furthermore, when at least one selected from the group consisting of PP, PA, ABS, PE, PC, POM, PBT, m-PPE, and PPS is a casing, it has excellent adhesion to a single layer and is moldable. It is preferable because it has excellent mechanical strength after molding and has heat resistance enough to withstand laser irradiation when forming metal wiring.

  The deflection temperature under load of the resin support is preferably 400 ° C. or less, more preferably 280 ° C. or less, and further preferably 250 ° C. or less. A support having a deflection temperature under load of 400 ° C. or lower is available at low cost, and is significant and preferable from the viewpoint of business. The deflection temperature under load is, for example, compliant with JIS K7191.

  The thickness of the support can be, for example, 1 μm to 10 mm, preferably 25 μm to 250 μm. It is preferable that the thickness of the support is 250 μm or less because the electronic device to be manufactured can be reduced in weight, space-saving, and flexible.

  In addition, when a support body is a housing | casing, the thickness can be 1 micrometer-10 mm, for example, Preferably, it is 200 micrometers-5 mm. By selecting this range, the present inventors have revealed that the mechanical strength and heat resistance after molding are expressed.

(Single layer)
The single layer is a mixture of an insulating region containing copper oxide particles and a phosphorus-containing organic substance and a metal wiring containing copper.

(Copper oxide particles)
In the present embodiment, the copper oxide includes, for example, cuprous oxide and cupric oxide. Cuprous oxide is particularly preferable because it tends to be sintered at a low temperature. These cuprous oxides and cupric oxides may be used alone or in combination.

  The copper oxide particles have a core / shell structure, and either the core or the shell may be cuprous oxide, or may contain cupric oxide.

  The copper oxide contained in the insulating region has, for example, a fine particle shape. The average particle diameter of the fine particles containing copper oxide is 1 nm to 100 nm, more preferably 1 nm to 50 nm, and still more preferably 1 nm to 20 nm. The smaller the particle diameter, the better the electrical insulation of the insulating region, which is preferable.

  In the single layer, the insulating region may contain copper particles. That is, you may add copper to the below-mentioned dispersion. Phosphorus-containing organic substances are adsorbed on the surface of the copper particles, and electrical insulation can be exhibited.

(Phosphorus-containing organic matter)
The phosphorus-containing organic material is a material that exhibits electrical insulation in the insulating region. It is preferable that the phosphorus-containing organic substance can fix copper oxide to the support. The phosphorus-containing organic substance may be a single molecule or a mixture of a plurality of types of molecules. Further, the phosphorus-containing organic substance may be adsorbed on copper oxide fine particles.

  The number average molecular weight of the phosphorus-containing organic material is not particularly limited, but is preferably 300 to 300,000. If it is 300 or more, it is excellent in electrical insulation.

  It is preferable that the phosphorus-containing organic substance is easily decomposed or evaporated by light or heat. By using an organic substance that is easily decomposed or evaporated by light or heat, a residue of the organic substance is less likely to remain after firing, and a metal wiring having a low resistivity can be obtained.

  The decomposition temperature of the phosphorus-containing organic substance is not limited, but is preferably 600 ° C. or lower, more preferably 400 ° C. or lower, and further preferably 200 ° C. or lower. The boiling point of the phosphorus-containing organic material is not limited, but is preferably 300 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 150 ° C. or lower.

  Although the absorption characteristic of a phosphorus containing organic substance is not limited, It is preferable that the light used for baking can be absorbed. For example, when laser light is used as a light source for firing, it is preferable to use a phosphorus-containing organic substance that absorbs light having an emission wavelength of, for example, 355 nm, 405 nm, 445 nm, 450 nm, 532 nm, or 1064 nm. When the support is a resin, the wavelengths of 355 nm, 405 nm, 445 nm, 450 nm, and 532 nm are particularly preferable.

  The structure is preferably a phosphate ester salt of a high molecular weight copolymer having a group having an affinity for copper oxide. For example, the structure of the chemical formula (1) is preferable because it adsorbs with copper oxide and is excellent in adhesion to a support.

  As an example of the ester salt, the structure of the chemical formula (2) can be given.

  Moreover, the structure of Chemical formula (3) can be mentioned as an example of a phosphorus containing organic substance.

  The organic structure of the phosphorus-containing organic substance includes polyethylene glycol (PEG), polypropylene glycol (PPG), polyimide, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC ), Polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal, polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), polyphenylene sulfide (PPS) ), Polyether ketone (PEK), polyphthalamide (PPA), polyether nitrile (PENt), polybenzimidazole (PBI), polycarbodi , Polysiloxane, polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, phenol resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA), polybutene, polypentene, ethylene-propylene copolymer Polymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE) , Polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), phenol novolac, benzocyclobutene, polyvinyl phenol, polychloropyrene, polyoxy Methylene, polysulfone (PSF), polysulfide, silicone resins, can be used aldose, cellulose, amylose, pullulan, dextrin, glucan, fructans, the structure of chitin. A structure obtained by modifying a functional group of these structures can be used, a structure obtained by modifying these structures can be used, and a copolymer of these structures can also be used. A phosphorus-containing organic substance having a skeleton selected from a polyethylene glycol structure, a polypropylene glycol structure, a polyacetal structure, a polybutene structure, and a polysulfide structure is preferable because it easily decomposes and does not easily leave a residue in a metal wiring obtained after firing.

  As a specific example of the phosphorus-containing organic substance, a commercially available material can be used. Specifically, DISPERBYK (registered trademark) -102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-109, DISPERBYK-110 manufactured by Big Chemie. DISPERBYK-111, DISPERBYK-118, DISPERBYK-140, DISPERBYK-145, DISPERBYK-168, DISPERBYK-180, DISPERBYK-182, DISPERBYK-187, DISPERBYK-191, DISPERBYK-191, DISPERBYK-191, DISPERBYK-191, DISPERBYK-191 -199, DISPERBYK-2000, DISPERBYK-200 DISPERBYK-2008, DISPERBYK-2009, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2013, DISPERBYK-2015, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK-2050, 152 -2061, DISPERBYK-2164, DISPERBYK-2096, DISPERBYK-2200, BYK-405, BYK-607, BYK-9076, BYK-9077, BYK-P105, Prisurf (registered trademark) M208F manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Plysurf DBS etc. can be mentioned. These may be used alone or in combination.

  A commercial item may be used for the copper oxide contained in the insulation area | region in this embodiment, and a synthetic material may be used for it. As a commercial item, the cuprous oxide microparticles | fine-particles with an average primary particle diameter of 18 nm currently sold from EM Japan are mentioned, for example.

Examples of the method for synthesizing fine particles containing cuprous oxide include the following methods.
(1) Add water and a copper acetylacetonate complex to a polyol solvent, once dissolve the organic copper compound by heating, add further water in an amount necessary for the reaction, and heat to the reduction temperature of the organic copper for reduction. Method.
(2) A method of heating an organic copper compound (copper-N-nitrosophenylhydroxylamine complex) at a high temperature of about 300 ° C. in an inert atmosphere in the presence of a protective agent such as hexadecylamine.
(3) A method of reducing a copper salt dissolved in an aqueous solution with hydrazine.

  The method of (1) is described in, for example, Angelevante Chemi International Edition, No. 40, Volume 2, p. 359, 2001.

  The method of (2) is described, for example, in Journal of American Chemical Society 1999, 121, p. It can be carried out under the conditions described in 11595.

  In the method (3), a divalent copper salt can be suitably used as the copper salt. Examples thereof include copper (II) acetate, copper (II) nitrate, copper (II) carbonate, Examples thereof include copper (II) chloride and copper (II) sulfate. The amount of hydrazine used is preferably 0.2 mol to 2 mol, more preferably 0.25 mol to 1.5 mol, per 1 mol of copper salt.

  A water-soluble organic substance may be added to the aqueous solution in which the copper salt is dissolved. Since the melting point of the aqueous solution is lowered by adding a water-soluble organic substance to the aqueous solution, reduction at a lower temperature becomes possible. As the water-soluble organic substance, for example, alcohol, water-soluble polymer and the like can be used.

  As the alcohol, for example, methanol, ethanol, propanol, butanol, hexanol, octanol, decanol, ethylene glycol, propylene glycol, glycerin and the like can be used. As the water-soluble polymer, for example, polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol copolymer and the like can be used.

  The temperature at the time of reduction in the method (3) can be, for example, −20 to 60 ° C., and preferably −10 to 30 ° C. This reduction temperature may be constant during the reaction, or may be raised or lowered during the reaction. In the initial stage of the reaction when the activity of hydrazine is high, the reduction is preferably 10 ° C. or less, and more preferably 0 ° C. or less. The reduction time is preferably 30 minutes to 300 minutes, and more preferably 90 minutes to 200 minutes. The atmosphere during the reduction is preferably an inert atmosphere such as nitrogen or argon.

  Among the methods (1) to (3), the method (3) is preferable because the operation is simple and particles having a small particle diameter are obtained.

(Metal wiring)
For example, copper in the metal wiring may have a structure in which fine particles containing copper are fused to each other. Moreover, there may be no shape of microparticles | fine-particles and it may be in the state which all fuse | melted. Furthermore, a part may be in the form of fine particles, and the majority may be in a fused state.

  In addition to copper, the metal wiring may contain copper oxide (cuprous oxide, cupric oxide, cuprous oxide) or phosphorus-containing organic matter. For example, the surface side portion of the metal wiring may have a structure in which fine particles containing copper are fused to each other, and the support side portion may have a structure containing copper oxide or a phosphorus-containing organic substance. Thereby, since a copper oxide or a phosphorus containing organic substance produces the strong coupling | bonding of copper particles, and also a copper oxide or a phosphorus containing organic substance can improve adhesiveness with a support body, it is preferable.

  The copper content in the metal wiring is preferably 50% by volume or more, more preferably 60% by volume or more, still more preferably 70% by volume or more, and 100% by volume with respect to the unit volume. Also good. It is preferable that the copper content is 50% by volume or more because the electrical conductivity is increased.

<Manufacturing method of metal wiring>
In the method for manufacturing a metal wiring body according to the present embodiment, for example, first, a support having a surface containing copper oxide particles is prepared. For example, first, a layer to be treated (copper oxide ink layer) containing copper oxide particles and a phosphorus-containing organic substance is disposed on the surface constituting the support. As this method, (a) a method of applying a dispersion (copper oxide ink) containing copper oxide particles and phosphorus-containing organic matter, (b) a method of spraying copper oxide particles and then applying phosphorus-containing organic matter, c) A method in which a phosphorus-containing organic material is applied and then copper oxide particles are dispersed is used. Hereinafter, the method (a) will be described as an example, but the method is not limited thereto.

(Dispersion preparation method)
Next, a method for preparing the dispersion will be described first. First, a copper oxide dispersion (copper oxide ink) in which copper oxide particles are dispersed in a dispersion medium together with a phosphorus-containing organic substance is prepared.

  For example, the copper oxide particles synthesized by the method (3) are soft agglomerates and are not suitable for coating as they are, so they need to be dispersed in a dispersion medium.

  After the synthesis is completed by the method (3), the synthesis solution and the copper oxide particles are separated by a known method such as centrifugation. To the obtained copper oxide particles, a dispersion medium and a phosphorus-containing organic substance are added and stirred by a known method such as a homogenizer to disperse the copper oxide particles in the dispersion medium.

  The phosphorus-containing organic substance according to the present embodiment functions as a dispersant. However, another dispersant may be added as long as it does not affect the electrical insulation of the insulating region.

  Depending on the dispersion medium, the copper oxide particles are difficult to disperse and may not be sufficiently dispersed. In such a case, for example, an easily dispersible alcohol such as butanol is used to disperse the copper oxide, followed by substitution with a desired dispersion medium and concentration to a desired concentration. As an example, there is a method in which concentration by a UF membrane and dilution and concentration by a desired dispersion medium are repeated.

(Application)
A thin film (hereinafter referred to as a layer to be processed) made of the dispersion according to the present embodiment is formed on the surface of the support as described above. More specifically, for example, the dispersion is applied onto a support, and if necessary, the dispersion medium is removed by drying to form a layer to be treated. A method for forming the layer to be treated is not particularly limited, and coating methods such as die coating, spin coating, slit coating, bar coating, knife coating, spray coating, and dip coating can be used. It is desirable to apply the dispersion with a uniform thickness on the support using these methods.

(Baking process)
In the present embodiment, copper oxide particles are reduced to form copper particles, and heat treatment is performed under conditions in which the produced copper particles are integrated by sintering (fusion) to form metal wiring. To do. This process is called a baking process.

(Metal wiring manufacturing equipment)
FIG. 4 is a schematic diagram showing an example of a metal wiring manufacturing apparatus according to the present embodiment. As shown in FIG. 4, the metal wiring manufacturing apparatus 30 includes a laser light source 31 that is an example of a light source.

(Galvano scanner)
The laser light 32 emitted from the laser light source 31 is input to a galvano scanner 33 which is an example of a light beam scanning unit. The galvano scanner 33 includes an X-axis galvano mirror 33a, an X-axis galvano motor 33b, a Y-axis galvano mirror 33c, and a Y-axis galvano motor 33d. Further, an fθ lens and a Z-axis adjusting drive lens (not shown) may be provided.

  The X-axis galvano motor 33b and the Y-axis galvano motor 33d of the galvano scanner 33 are electrically connected to a scanner control unit 34, which is an example of a speed control unit.

  The galvano scanner 33 is configured to be able to control the rotation angle and rotation speed of the X-axis galvano motor 33b and the Y-axis galvano motor 33d in accordance with a control signal from the scanner control unit 34.

  The laser beam 32 is scanned by the galvano scanner 33 and irradiated onto the surface of the layer to be processed 36 containing copper oxide particles and a dispersant, which is formed on the substrate 35 as an example of a support.

  In the present embodiment, the galvano scanner 33 uses the X-axis and Y-axis galvanometer mirrors 33a and 33c for movement in the X-axis direction and the Y-axis direction. The movement may be performed by using a galvanometer mirror and moving the Y-axis direction by moving a mounting table (not shown) on which the substrate 35 is mounted along the Y-axis direction with a motor or the like.

  Here, the galvano scanner 33 has been described as an example of the light beam scanning unit, but is not particularly limited. For example, the light beam scanning unit uses an XY stage that can move the substrate 35 provided with the layer to be processed 36 in both the X-axis direction and the Y-axis direction as a mounting table instead of the galvano scanner 33. Instead of moving the irradiation point P, the substrate 35 may be moved.

(Scanning speed control)
The scanning speed control in the metal wiring manufacturing apparatus 30 as described above will be described. First, scan data (coordinate data) indicating a desired metal wiring pattern (shape, position, and size) is input to the scanner controller 34. The scanner control unit 34 calculates the length (L) (unit: mm) of the scanning line from the length along the X-axis direction of the pattern based on the scanning data. Next, based on the calculated length (L) of the scanning line, the scanner control unit 34 uses the following equation (1) to set a predetermined scanning period (F) (unit: Hz) (for example, 15 Hz). Thus, the scanning speed (hereinafter referred to as scanning speed) (V) (unit: mm / second) of the laser beam is calculated.
Scanning speed (V) = scanning cycle (F) x length of scanning line (L) (1)

  Next, the scanner control unit 34 causes the galvano scanner 33 to move the irradiation point P (see FIG. 4) of the laser light 32 in the X-axis direction in accordance with the scanning speed calculated in this way, and execute one scan. .

  Thereafter, the scanner control unit 34 causes the galvano scanner 33 to move the irradiation point P of the laser light 32 in the Y-axis direction.

  As described above, the scanning speed (V) of the laser beam 32 is always based on the length (L) of the scanning line, that is, at any point A or B in the metal wiring 1 (see FIG. 1). The scanning cycle (F) can be set to be the same.

  Thus, by changing the scanning speed (V) according to the length (L) of the scanning line Ia constituting the metal wiring 1, as described with reference to FIG. In this case, it is possible to suppress variation in sintering degree of copper particles (an example of metal particles) generated by reduction of copper oxide particles, and uniform resistance value of the metal wiring 1 in the region 1a and the region 1b. Can be.

  In this embodiment, the scanning cycle (F) does not need to be exactly the same, and if the resistance value of the metal wiring can be made uniform to the extent that there is no practical problem, the scanning cycle (F) varies. There may be. Therefore, in this embodiment, the scanning speed (V) may be set so that the scanning periods (F) are substantially the same.

(Scan line overlap)
Further, as described above, the amount of movement of the irradiation point P (see FIG. 4) of the laser beam 32 in the Y-axis direction can be arbitrarily set, but in the present embodiment, adjacent scanning lines overlap each other. It is preferable to set the amount of movement to be performed. FIG. 5 is a schematic diagram showing scanning lines overlapping each other in the metal wiring manufacturing method according to the present embodiment. As shown in FIG. 5, a certain scanning line 41 and a scanning line 42 adjacent thereto overlap each other. This increases the amount of heat storage in the overlapping region where the scanning lines 41 and 42 overlap, thereby increasing the degree of sintering of the copper particles and, as a result, lowering the resistance value of the metal wiring 1 (see FIG. 1). Can do.

  The ratio of the width W2 of the region where the scanning lines 41 and 42 overlap with the width W1 (for example, 320 μm) of the scanning lines 41 and 42 is defined as an overlap ratio (%) with the scanning lines 41 and 42. The overlap ratio is preferably in the range of 5% to 99.5%, more preferably in the range of 10% to 99.5%, and further in the range of 15% to 99.5%. preferable. When the overlap ratio is 5% or more, the degree of sintering of copper particles can be increased, and when it is 99.5% or less, sintering is performed while moving in the Y-axis direction at an industrially practical speed. can do.

  If the adjacent scanning lines Ia overlap each other by scanning with the laser beam 32 (see FIG. 4), as shown in FIG. 1, the scanning direction, that is, the moving direction along the X axis of the irradiation point (FIG. 1 (indicated by an arrow D in FIG. 1) may be in opposite directions or in the same direction.

  The structure with metal wiring according to the present embodiment manufactured as described above is formed by sintering copper oxide particles on a surface containing copper oxide, which is an example of metal particles, by repeated scanning of light. The metal wiring 1 (see FIG. 1) is formed so that the adjacent scanning lines Ia overlap each other.

  Since the metal wiring 1 manufactured with such a configuration can have a higher degree of sintering than those having a small overlap rate, the metal wiring 1 is not brittle and can be made hard. For example, when the metal wiring 1 is formed on a flexible substrate and bent, the metal wiring 1 can follow the flexible substrate without being broken.

(Light collection control)
In the above baking treatment, there is an optimum wavelength according to the light absorption wavelength of the metal particles. Since the wavelength can be freely selected by performing the sintering of the metal particles with the laser beam, the light having a wavelength suitable for the sintering can be irradiated, and the metal particles can be effectively sintered. However, when light having an optimum wavelength is selected, the output necessary for sintering the metal particles may not be obtained, and sintering may be insufficient.

  For example, for a layer to be treated containing copper oxide particles, an output of about 10 to 20 W is required with a continuous wave (CW, Continuous Wave) of 400 nm or more and 532 nm or less. On the other hand, it is difficult to obtain light having an optimum wavelength and optimum output with a single light source. Therefore, in the present embodiment, by converging a plurality of light beams, a light beam having a wavelength suitable for sintering of the metal particles can be applied to the processing layer including the metal particles with an output suitable for sintering. It is preferable to make it.

  As a result, since a plurality of light beams can be focused, the surface including the metal particles can be irradiated with light in a state where the output is increased to a value suitable for sintering of the metal particles, and the metal particles are effectively sintered, A low-resistance metal wiring 1 (see FIG. 1) can be obtained.

(Focusing control unit)
Moreover, it is preferable to focus a light beam on the surface containing a metal particle using the focusing control part arrange | positioned between a light source and the surface containing a metal particle (refer FIG.4 and FIG.6). Thereby, a some light beam can be easily focused on the surface containing a metal particle, without adjusting the position of a light source.

  In the focusing control unit, it is preferable that at least one light beam is transmitted and the remaining light beam is reflected and focused on the surface including the metal particles. Since multiple light beams can be applied to the surface containing metal particles in a state of being superimposed on the same optical axis, multiple light beams that have been collected are collected rather than focusing each light beam that is emitted from different positions within the surface. The area that hits the surface containing the metal particles is reduced, and the surface containing the metal particles can be finely patterned.

  Such a focusing control unit is preferably a wavelength selection member such as a wavelength selection mirror or a wavelength selection prism (see FIG. 7A). The wavelength selection member focuses light beams having different wavelengths. That is, it reflects light in a specific wavelength range and transmits light in other wavelength ranges. For example, when the wavelengths of two light beams are different from each other, the wavelength selection member can transmit a light beam in one wavelength region and reflect a light beam in the other wavelength region. Thereby, the light beams having different wavelength ranges can be superimposed on the same optical axis and focused on the surface including the metal particles. Specifically, a dichroic mirror or a dichroic prism can be used as the wavelength selection member.

  Moreover, as a focusing control part, it is preferable that it is a reflective polarizing plate, for example (refer FIG. 7B). The reflective polarizing plate focuses laser beams having different polarizations. Thus, for example, even if the wavelengths of the two light beams are the same, if the polarizations of the two light beams are different from each other, the reflective polarizing plate transmits the light beam of one polarization and reflects the light beam of the other polarization. Can do. That is, the reflective polarizing plate transmits, for example, S-polarized light and reflects P-polarized light. Thereby, the light beams having different polarizations can be superimposed on the same optical axis and focused on the surface including the metal particles.

  The reflective polarizing plate may be configured to transmit either one of S-polarized light and P-polarized light and reflect the other. As the reflective polarizing plate, for example, a wire grid polarizer can be used. For example, if the polarization of two light beams are different from each other, the reflective polarizing plate can superimpose the two light beams on the same optical axis even when the wavelengths of the two light beams are different from each other.

  Further, in the focusing control unit having the incident surface and the exit surface, it is preferable that a plurality of light beams are incident on the entrance surface and emitted from the exit surface to be focused on the surface including the metal particles. Since a plurality of light beams can be focused with a simple configuration, the number of light sources can be easily increased, and the output can be effectively increased. Moreover, even if it is a light ray from which a wavelength mutually differs, even if it is a light ray with the same wavelength, it can focus.

  Such a focusing control unit is preferably a lens, for example (see FIG. 7C). If a plurality of light beams are incident on the lens and emitted, the plurality of light beams can be focused and condensed on the surface including the metal particles. From the viewpoint of effectively increasing the output of the light beam to a value suitable for sintering of the metal particles, it is preferable that two or more light beams are converged by a lens, more preferably three or more light beams. More preferably, it is one or more light beams.

  Further, the lens can focus even light rays having different wavelengths or light rays having the same wavelength. Since the position of the lens can be easily adjusted with respect to the surface containing the metal particles, the focal position of the light beam focused in the surface containing the metal particles can be adjusted.

  Next, the configuration of the focusing control unit and the laser beam focusing method of the focusing control unit will be described in detail with reference to FIG. FIG. 6 is an explanatory diagram of the metal wiring manufacturing apparatus according to the present embodiment. FIG. 7 is an explanatory diagram of the focusing control unit according to the present embodiment. 7A shows a case where a wavelength selection mirror or wavelength selection prism is used as the focusing control unit, FIG. 7B shows a case where a reflective polarizing plate is used, and FIG. 7C shows a case where a lens is used. In FIG. 7, the light beam scanning unit 57 is omitted.

  As shown in FIG. 6, the metal wiring manufacturing apparatus 50 includes laser light sources 51 and 52, and a focusing control unit 55 that focuses the laser beams 53 and 54 emitted from the laser light sources 51 and 52. The The focusing control unit 55 is disposed between the laser light sources 51 and 52 and the structure 56 composed of the substrate 56a and the processing target layer 56b, and outputs the laser beams 53 and 54 emitted from the laser light sources 51 and 52, respectively. Then, control is performed so as to focus on the layer to be processed 56b formed on the surface of the substrate 56a. The laser beams 53 and 54 focused by the focusing control unit 55 are transmitted by an X-axis galvano mirror 33a and a Y-axis galvano mirror 33b (see FIG. 4) constituting a galvano scanner 33 (see FIG. 4) which is an example of a light beam scanning unit. The processed layer 56b is irradiated with the scanning. There may be a lens for condensing the focused laser beam between the beam scanning unit 57 and the structure 56.

  The laser beams 53 and 54 emitted from the laser light sources 51 and 52 are focused by the focusing control unit 55 and are incident on the light beam scanning unit 57. The focused laser beams 53 and 54 are scanned by the light beam scanning unit 57 onto the processing target layer 56b formed on the surface of the substrate 56a.

  In this way, for example, since the two laser beams 53 and 54 can be focused by the focusing control unit 55, the laser beams 53 and 54 are processed in a state where the output is increased to a value suitable for sintering of copper particles. 56b can be irradiated. Therefore, the copper particles of the layer to be treated 56b can be effectively sintered to form a low resistance metal wiring. Further, by using the focusing control unit 55, the laser beams 53 and 54 can be easily focused on the processing layer 56b without adjusting the positions of the laser light sources 51 and 52. Further, since the laser beams 53 and 54 focused on the focusing control unit 55 are scanned by the beam scanning unit 57 on the processing target layer 56b, the processing target layer 56b is sintered into a desired pattern, and has a desired shape. Metal wiring can be formed.

  It is preferable that at least two laser light sources 51 and 52 are provided, and two or more laser light sources 51 and 52 are used for focusing the emitted laser beams 53 and 54 to increase the output to a value suitable for sintering of metal particles. Laser light sources 51 and 52 are preferably provided. From the viewpoint of obtaining an output of 10-20 W suitable for sintering of copper particles, it is most preferable that four or more laser light sources 51, 52 are provided.

  The laser light sources 51 and 52 have a degree of freedom in selecting the wavelengths of the laser beams 53 and 54, and can be selected in consideration of the light absorption wavelength of the processing target layer 56b and the absorption wavelength of the substrate 56a. Laser types include YAG (yttrium, aluminum, garnet), YVO (yttrium vanadate), Yb (ytterbium), semiconductor laser (GaAs, GaAlAs, GaInAs, GaN, InGaN, AlGaN, etc.), carbon dioxide gas, fiber laser, etc. In addition to the fundamental wave, harmonics may be extracted and used as necessary. From the viewpoint of emitting laser beams 53 and 54 having a center wavelength of 400 nm or more and 550 nm or less that can effectively sinter the copper particles contained in the layer to be processed 56b, it is more preferable to use a semiconductor laser or a second harmonic. The laser beams 53 and 54 can be a pulsed wave (Pulsed Operation) or a continuous wave (CW). The sintering of the copper particles in the layer to be treated 56b is irradiated with a continuous wave. Is preferred.

  Further, exposure by beam scanning is possible, and adjustment of the exposure range such as exposure to the entire surface of the processing target layer 56b or selection of partial exposure is easy. The amount of exposure can be adjusted by the light intensity, the light emission time, the light irradiation interval, and the number of times, and if the light transmission of the substrate 56a is large, it can be applied to a resin substrate having low heat resistance, such as PET, PEN, paper, The wiring 1 (see FIG. 1) can be formed.

  In particular, the emission wavelengths of the laser beams 53 and 54 are preferably such that the center wavelength is not less than 355 nm and not more than 550 nm. By irradiating laser beams 53 and 54 having a wavelength in this range, the metal particles can be effectively sintered when the treated layer 56a contains metal particles such as copper, silver, gold, and aluminum. The emission wavelengths of the laser beams 53 and 54 are preferably such that the center wavelength is not less than 400 nm and not more than 550 nm. Thereby, the copper particle contained in the to-be-processed layer 56b can be sintered effectively. The wavelengths of the laser beams 53 and 54 are preferably 355 nm, 405 nm, 445 nm, 450 nm, and 532 nm, for example, when the substrate 56 a is a resin. Thus, the metal wiring manufacturing apparatus 50 irradiates the laser beams 53 and 54 having a center wavelength suitable for sintering of the copper particles of the layer to be processed 56b of 400 nm or more and 550 nm or less with an output suitable for sintering of the copper particles. it can.

  As shown in FIGS. 7A and 7B, the focusing control unit 55 transmits the laser light 53 emitted from the laser light source 51, reflects the laser light 54 emitted from the laser light source 52, and causes the laser lights 53 and 54 to be reflected. It is good also as a structure converged on the to-be-processed layer 56b.

  Such a focusing control unit 55 is preferably, for example, a wavelength selection member 61 as shown in FIG. 7A. The wavelength selection member 61 focuses laser beams having different wavelengths. That is, light of a specific wavelength is reflected and light of other wavelengths is transmitted. Therefore, when the wavelengths of the laser light 53 emitted from the laser light source 51 and the laser light 54 emitted from the laser light source 52 are different, the wavelength selection member 61 transmits the laser light 53 from the laser light source 51, for example, By reflecting the laser beam 54 having a wavelength different from that of the laser beam 53 from the laser light source 52, the laser beams 53 and 54 are superimposed on the same optical axis and condensed on the processing layer 56b. If the laser beams 53 and 54 having different wavelengths can be focused, two or more wavelength selection members 61 may be provided. Thereby, since the laser light sources 51 and 52 can be increased and the plurality of laser lights 53 and 54 can be focused, the output of the laser light sources 51 and 52 can be effectively increased to a value suitable for sintering of metal particles.

  A mirror 58 (FIG. 6) or the like is disposed between the wavelength selection member 61 and the laser light source 52, and the laser light 54 emitted from the laser light source 52 is reflected by the mirror 58 to the wavelength selection member 61. It may be incident or may be directly incident on the wavelength selection member 61 from the laser light source 52. In FIG. 7B, the same applies to the case where a reflective polarizing plate 62 is used as the light collection control unit 55.

  Further, as shown in FIG. 7B, the focusing control unit 55 is preferably a reflective polarizing plate 62, for example. The reflective polarizing plate 62 focuses differently polarized laser beams. Therefore, even when the laser light 53 emitted from the laser light source 51 and the laser light 54 emitted from the laser light source 52 have the same wavelength, if the laser light 53 and the laser light 54 are made to have different polarizations, The reflective polarizing plate 62 can transmit, for example, the laser light 53 from the laser light source 51 and reflect the laser light 54 having a polarization different from that of the laser light 53 from the laser light source 52. That is, for example, the reflective polarizing plate 62 transmits the S-polarized laser beam 53 and reflects the P-polarized laser beam 54. Thereby, the reflective polarizing plate 62 can condense the laser beams 53 and 54 on the same layer 56b on the processing target layer 56b.

  The reflective polarizing plate 62 may be configured to transmit one of S-polarized light and P-polarized light and reflect the other. As the reflective polarizing plate 62, for example, a wire grid polarizer can be used.

  The laser beams 53 and 54 are emitted from the laser light sources 51 and 52, changed into different polarizations by a polarizer (not shown), and then incident on the reflective polarizing plate 62. Further, when the laser beams 53 and 54 have different polarizations, the reflective polarizing plate 62 superimposes the laser beams 53 and 54 on the same optical axis even when the wavelengths of the laser beams 53 and 54 are different from each other. be able to.

  7A and 7B, when the wavelength selection member 61 and the reflective polarizing plate 62 are used as the light collection control unit 55, the laser beams 53 and 54 can be superimposed on the same optical axis. 56b can be finely patterned.

  As shown in FIG. 7C, the focusing control unit 55 may be configured to focus the laser beams 53 and 54 on the processing layer 56b using, for example, a lens 63.

  The lens 63 has an entrance surface 63a and an exit surface 63b. The lens 63 causes the laser beams 53 and 54 to be incident on the incident surface 63a and the laser beams 54 and 55 to be emitted from the emission surface 63b, thereby condensing the laser beams 53 and 54 on the processing layer 56b. The lens 63 is preferably a convex lens, a concave lens, or an uneven surface. For example, a concave lens is more preferable because the optical axis can be easily adjusted. The size of the lens 63 can be adjusted by the number of laser light sources 51 and 52 used.

  If the laser light is incident on and emitted from the lens 63, the lens 63 can condense the plurality of laser lights 53 and 54 emitted from the two or more laser light sources 51 and 52 onto the processing layer 56b. From the viewpoint of effectively increasing the output of the laser light sources 51 and 52 to a value suitable for sintering of metal particles, the laser beams 53 and 54 emitted from the two or more laser light sources 51 and 52 are condensed by the lens 63. It is more preferable that three or more laser light sources are used, and four or more laser light sources 51 and 52 are used from the viewpoint of obtaining an output of 10 to 20 W suitable for sintering of copper particles. Most preferably.

  Since the lens 63 is used as the focusing control unit 55, the plurality of laser beams 53 and 54 can be focused with a simple configuration. Therefore, the number of the laser light sources 51 and 52 can be easily increased, and the output can be effectively increased. Further, even if the laser beams 53 and 54 have different wavelengths, the laser beams 53 and 54 having the same wavelength can be condensed. In addition, since the position of the lens 63 can be easily adjusted with respect to the processing target layer 56b, the focal positions of the focused laser beams 53 and 54 can be adjusted within the processing target layer 56b.

  With reference to FIG. 8, the manufacturing method of the support body with metal wiring which concerns on this Embodiment is demonstrated more concretely. FIG. 8 is explanatory drawing which shows each process of the manufacturing method of the support body with metal wiring which concerns on this Embodiment. In FIG. 8A, copper acetate is dissolved in a mixed solvent of water and propylene glycol (PG), and hydrazine is added and stirred.

  Next, in (b) and (c) in FIG. 8, the supernatant and the precipitate were separated by centrifugation. Next, in (d) of FIG. 8, a dispersing agent (phosphorus containing organic substance) and alcohol are added and disperse | distributed to the obtained deposit.

  Next, in (e) and (f) in FIG. 8, the concentration and dilution by the UF membrane module are repeated, the solvent is replaced, and a dispersion I containing copper oxide particles is obtained.

In (g) and (h) in FIG. 8, dispersion I was coated on a PET support (described as “PET” in FIG. 8 (h)) by spray coating, and contained copper oxide and phosphorus. A coating layer (processed layer) containing an organic substance (described as “Cu ₂ O” in FIG. 8H) is formed.

  Next, in FIG. 8 (i), the coating layer is irradiated with laser, a part of the coating layer is selectively baked, and copper oxide is described as copper (in FIG. 8 (i), “Cu”). Reduced). As a result, in FIG. 8J, an insulating region containing copper oxide and a phosphorus-containing organic substance (described as “A” in FIG. 8J) and a metal wiring containing copper (FIG. 8) are formed on the support. 8 (j), described as “B”), a structure with metal wiring is obtained in which a single layer is formed adjacent to each other.

<Application example>
The structure with metal wiring according to the present embodiment is formed in, for example, a wiring material such as an electronic circuit board (printed circuit board, RFID, substitute for a wire harness in an automobile, etc.) or a casing of a portable information device (smartphone or the like). The present invention can be suitably applied to antennas, mesh electrodes (capacitance-type electrode films for touch panels), electromagnetic shielding materials, and heat dissipation materials.

  As described above, according to the metal wiring manufacturing method and the metal wiring manufacturing apparatus according to the present embodiment, the light beam depends on the length (L) of the scanning line Ia constituting the metal wiring 1 (see FIG. 1). By varying the scanning speed (V), it is possible to suppress variation in the degree of sintering of the metal particles and to easily obtain the metal wiring 1 having a uniform resistance value.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these Examples and a comparative example.

Example 1
<Copper oxide dispersion>
In a mixed solvent of 7560 g of distilled water (manufactured by Kyoei Pharmaceutical Co., Ltd.) and 3494 g of 1,2-propylene glycol (manufactured by Kanto Chemical Co., Ltd.), 806 g of copper acetate (II) monohydrate (manufactured by Kanto Chemical Co., Ltd.) was dissolved. . The resulting solution was brought to a liquid temperature of −5 ° C. with an external temperature controller. To the solution, 235 g (manufactured) of hydrazine monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added over 20 minutes and stirred for 30 minutes. Thereafter, the solution was brought to a liquid temperature of 25 ° C. with an external temperature controller and stirred for 90 minutes. After stirring, the solution was separated into a supernatant and a precipitate by centrifugation. 13.7 g of DISPERBYK-145 (manufactured by Big Chemie) (dispersant content 4 g), 54.6 g of Surflon S611 (manufactured by Seimi Chemical), and 907 g of ethanol (manufactured by Kanto Chemical Co., Ltd.) are added to 390 g of the obtained precipitate. And using a homogenizer, 1365 g of a cuprous oxide dispersion was obtained.

[Method for quantifying hydrazine]
The hydrazine was quantified by the standard addition method.

To 50 μL of a sample (copper nanoink), 33 μg of hydrazine, 33 μg of a surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of benzaldehyde 1% acetonitrile solution were added. Finally, 20 μL of phosphoric acid was added, and after 4 hours, GC / MS measurement was performed.

Similarly, 66 μg of hydrazine, 33 μg of surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ), and 1 ml of benzaldehyde 1% acetonitrile solution were added to 50 μL of the sample (copper nanoink). Finally, 20 μL of phosphoric acid was added, and after 4 hours, GC / MS measurement was performed.

Similarly, hydrazine 133 μg, surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ) 33 μg, and benzaldehyde 1% acetonitrile solution 1 ml were added to 50 μL of the sample (copper nanoink). Finally, 20 μL of phosphoric acid was added, and after 4 hours, GC / MS measurement was performed.

Finally, to 50 μL of the sample (copper nanoink), without adding hydrazine, 33 μg of surrogate substance (hydrazine ¹⁵ N ₂ H ₄ ) and 1 ml of benzaldehyde 1% acetonitrile solution were added, and finally 20 μL of phosphoric acid was added, and after 4 hours, GC / MS measurement was performed.

  The peak area value of hydrazine was obtained from the chromatogram of m / z = 207 from the above four GC / MS measurements. Next, the surrogate peak area value was obtained from the mass chromatogram of m / z = 209. The calibration curve by the standard addition method was obtained by taking the weight of added hydrazine / weight of added surrogate substance on the x-axis and the peak area value of hydrazine / the peak area value of the surrogate substance on the y-axis.

  The value of the Y-intercept obtained from the calibration curve was divided by the weight of added hydrazine / weight of added surrogate material to obtain the weight of hydrazine.

[Particle size measurement]
The average particle diameter of the copper oxide ink was measured by a cumulant method using FPAR-1000 manufactured by Otsuka Electronics.

  The dispersion was well dispersed. The content of cuprous oxide was 20 g, and the particle size was 21 nm. The amount of hydrazine was 3000 ppm.

<Coating film>
The obtained dispersion was applied to a polyimide film (manufactured by Toray DuPont, Kapton 500H, thickness 125 μm) by spin coating, and kept in an oven at 40 ° C. for 2 hours to volatilize the solvent in the coating film and sample 1 was obtained. The coating thickness of Sample 1 obtained was approximately 1000 nm.

<Metal wiring manufacturing equipment>
As a laser light source, two sets of semiconductor lasers having continuous wave oscillation (Continuous Wave: CW), a central wavelength of 445 nm, and an output of 2.0 W were prepared. Two types of laser beams were incident on one concave lens and adjusted so as to be focused on approximately one laser beam to obtain a combined laser beam. Further, the combined laser beam was incident on a galvano scanner and adjusted so that the surface of the coating film of Sample 1 was in focus. Note that the result of measuring the output of the combined laser beam was 3.6 W.

<Manufacture of metal wiring>
Pattern data combining rectangular areas (main scanning direction) having different sizes was prepared and input to a metal wiring manufacturing apparatus. The pattern data has a length in the main scanning direction of L1 = 20 mm and L2 = 10 mm, and a length (width) in the direction perpendicular to the main scanning direction is 3 mm. The scanning speed (V1, V2) was calculated as follows so that the scanning period (F) was 15 Hz, and the combined laser beam was scanned while controlling the scanning speed.
Scanning speed V1 = F × L1 = 300 mm / s
Scanning speed V2 = F × L2 = 150 mm / s

  Further, when the combined laser beam was reciprocally scanned in the main scanning direction, the movement pitch in the direction perpendicular to the main scanning direction was controlled so that the scanning line had an overlap rate of 96%.

  In the portion irradiated with the combined laser beam, the copper oxide in the coating film was reduced, and rectangular conductive patterns having different sizes made of reduced copper were obtained.

<Resistance measurement>
The obtained conductive pattern was cut in the region of L1 = 20 mm, width 3 mm, L2 = 10 mm, width 3 mm, and the specific resistance value was evaluated by a four-terminal measurement method. As a result, it was about 50 μΩcm regardless of the length of the conductive pattern, and the resistance was low enough to be used as a metal wiring.

<Observation of overlap part>
The surface of the obtained conductive pattern was observed with an optical microscope. The state of observation is shown in FIG. FIG. 9 is an optical micrograph of the surface of the conductive pattern in Example 1 of the present invention. By observation, the scanning lines of the coupled laser beam were confirmed at intervals of 13.2 μm. The width of the locus of the non-overlapping portion of the scanning end portion of the conductive pattern was 320 μm. The overlap ratio calculated by the following formula was 95.9%.
(Overlap ratio) = (320 μm−13.2 μm) ÷ 320 μm

(Example 2)
Using a continuous wave oscillation (Continuous Wave: CW), a center wavelength of 532 nm, and a laser beam output of 6.0 W as a laser light source, the scanning speed (V) is calculated so that the scanning period (F) is 20 Hz, and the scanning speed is calculated. A conductive pattern was obtained in the same manner as in Example 1 except that the combined laser beam was scanned while being controlled. The resistance was measured in the same manner as in Example 1. As a result, the resistance was approximately 70 μΩcm, which was sufficiently low for use as a metal wiring.

(Comparative Example 1)
A conductive pattern was obtained in the same manner as in Example 1 except that the scanning speed at the time of reciprocating scanning with the combined laser beam was not adjusted and scanning was performed at a constant speed of 300 mm / s. The obtained conductive pattern was cut in a region of L1 = 20 mm, width 3 mm, L2 = 10 mm, width 3 mm, and the specific resistance value was evaluated by a four-terminal measurement method. As a result, the specific resistance value in the region of L1 = 20 mm and the width of 3 mm was 50 μΩcm, and the region of L2 = 10 mm and the width of 3 mm was partially burned, so that the resistance measurement could not be performed. In the burned area, it is estimated that the scanning speed is slow, the amount of stored heat increases, and a part of the burned area is burnt.

(Comparative Example 2)
A conductive pattern was obtained in the same manner as in Example 1 except that when the sample 1 was irradiated while reciprocating scanning with a combined laser beam, scanning was performed with 3% overlap of the scanning lines. The obtained conductive pattern was cut in a region of L1 = 20 mm, width 3 mm, L2 = 10 mm, width 3 mm, and the specific resistance value was evaluated by a four-terminal measurement method. As a result, it was about 500 μΩcm regardless of the length of the conductive pattern, which was insufficient for use as a metal wiring. It is presumed that the resistance was high because the overlap was small and the degree of sintering of copper did not increase.

  In addition, this invention is not limited to the said embodiment and Example. Based on the knowledge of those skilled in the art, design changes or the like may be added to the above-described embodiments and examples, or the above-described embodiments and examples may be arbitrarily combined, and such changes are added. Embodiments are also within the scope of the present invention.

  For example, in the above-described embodiment, the copper oxide particles are described as an example of the metal particles. However, the present invention can be applied to the case where the surface including the metal particles is sintered to form the metal wiring. Accordingly, the metal particles include at least one selected from the group consisting of copper, silver, gold, and aluminum.

  The present invention is also applied to the case where a surface including metal oxide particles other than copper oxide particles (for example, fine particles such as iron oxide, magnesium oxide, nickel oxide) is sintered to form metal wirings and electrodes. be able to. In the present invention, when metal oxide particles are fired to form metal wiring, metal oxide particles are reduced to form metal particles, and when the metal particles are sintered to each other, the degree of reduction and sintering is reduced. It is possible to suppress the occurrence of variation and form a metal wiring having a uniform resistance value.

  Moreover, in the said embodiment, the to-be-processed layer containing a metal particle is formed on a support body, and the surface containing a metal particle is comprised. However, you may make it comprise the surface containing a metal particle by making a support body itself contain a metal particle.

  In the above-described embodiment, the case where the surface including the metal particles is formed from a dispersion including the metal particles and the phosphorus-containing organic material as the dispersant has been described as an example. However, the dispersant is other than the phosphorus-containing organic material. It may be a dispersing agent.

  According to the present invention, it is possible to provide a metal wiring manufacturing method, a structure with metal wiring, and a metal wiring manufacturing apparatus capable of easily obtaining a metal wiring having a uniform resistance value. Therefore, it can utilize suitably for manufacture of wiring materials, such as an electronic circuit board, a mesh electrode, an electromagnetic wave shielding material, and a thermal radiation material.

1, 23 Metal wiring 11, 36, 56a Processed layer 12 Copper oxide particles (metal particles)
13 Phosphate salt 20, 56 Structure with metal wiring (structure)
DESCRIPTION OF SYMBOLS 21 Support body 22 Insulation area | region 24 Single layer 30, 50 Metal wiring manufacturing apparatus 31, 51, 52 Laser light source (light source)
32, 53, 54 Laser light (light beam)
33 Galvano scanner (ray scanning part)
34 Scanner controller (speed controller)
35, 56b Substrate (support)
41, 42 Scan line 55 Convergence controller 61 Wavelength selection member 62 Reflective polarizing plate 63 Lens

Claims (27)

Scanning the light repeatedly on the surface containing the metal particles to sinter the metal particles, forming a metal wiring,
A method of manufacturing a metal wiring, wherein a scanning speed of the light beam is varied according to a length of a scanning line constituting the metal wiring.   The method of manufacturing a metal wiring according to claim 1, wherein the speed is set so that scanning periods are substantially the same.   The metal wiring manufacturing method according to claim 1, wherein the metal wiring is formed so that adjacent scanning lines overlap each other.   4. The method of manufacturing a metal wiring according to claim 3, wherein the scanning lines are overlapped by 5% to 99.5% in the width direction.   The method for manufacturing a metal wiring according to any one of claims 1 to 4, wherein the metal particles contain at least one selected from the group consisting of copper, silver, gold, and aluminum.   6. The method of manufacturing a metal wiring according to claim 1, wherein the metal particles are metal oxide particles.   The method of manufacturing a metal wiring according to claim 6, wherein the metal oxide particles are copper oxide particles.   8. The method of manufacturing a metal wiring according to claim 1, wherein the surface containing the metal particles is formed from a dispersion containing the metal particles and a dispersant.   The method for manufacturing a metal wiring according to claim 8, wherein the dispersant contains a phosphorus-containing organic substance.   The method of manufacturing a metal wiring according to any one of claims 1 to 9, wherein the light beam is a laser beam having a central wavelength of 355 nm or more and 550 nm or less.   The said metal particle is sintered by controlling so that each light ray radiate | emitted from the several light source may be converged on the surface containing the said metal particle, The Claim 1-10 characterized by the above-mentioned. Metal wiring manufacturing method.   The metal according to claim 11, wherein the light beam is focused on the surface including the metal particles using a focusing control unit disposed between the light source and the surface including the metal particles. Wiring manufacturing method.   13. The method of manufacturing a metal wiring according to claim 12, wherein the focusing control unit transmits at least one of the light beams and reflects the remaining light beams to focus on the surface including the metal particles.   The method of manufacturing a metal wiring according to claim 13, wherein the focusing control unit is a wavelength selection member and focuses the light beams having different wavelengths.   The method of manufacturing a metal wiring according to claim 13, wherein the focusing control unit is a reflective polarizing plate and focuses the light beams having different polarizations.   The focusing control unit having an entrance surface and an exit surface, wherein a plurality of the light beams are incident on the entrance surface, exit from the exit surface, and converge on the surface including the metal particles. 12. A method for producing a metal wiring according to 12.   The method of manufacturing a metal wiring according to claim 16, wherein the focusing control unit is a lens.   The method of manufacturing a metal wiring according to any one of claims 11 to 17, wherein the light beam is a laser beam having a center wavelength of 355 nm or more and 550 nm or less.   The surface including the metal particles is provided with a metal wiring formed by sintering the metal particles by repeated scanning of light, and the metal wiring is formed so that adjacent scanning lines overlap each other. A structure with metal wiring.   The structure with metal wiring according to claim 19, wherein the scanning lines overlap by 5% to 99.5% in the width direction.   A light beam scanning unit that repeatedly scans light on a surface including metal particles to form a metal wiring, and a speed at which the light beam scanning unit scans the light beam varies depending on the length of the scanning line that forms the metal wiring. A metal wiring manufacturing apparatus, comprising: a speed control unit.   The metal according to claim 21, further comprising: a plurality of light sources; and a focusing control unit that controls each of the light beams emitted from the plurality of light sources to focus on a surface including the metal particles. Wiring manufacturing equipment.   23. The metal wiring manufacturing apparatus according to claim 22, wherein the focusing control unit is a wavelength selection member.   23. The metal wiring manufacturing apparatus according to claim 22, wherein the focusing control unit is a reflective polarizing plate.   The metal wiring manufacturing apparatus according to claim 22, wherein the focusing control unit is a lens.   25. The metal wiring manufacturing apparatus according to claim 21, wherein the light source emits a laser beam having a center wavelength of 355 nm to 550 nm. 26. The metal wiring manufacturing apparatus according to claim 25, wherein the central wavelength is not less than 400 nm and not more than 532 nm.

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