JP6507743B2 - Wiring structure, method of manufacturing wiring structure, and electronic device - Google Patents

Description

  The present invention relates to a wiring structure, a method of manufacturing the wiring structure, and an electronic device.

  2. Description of the Related Art In recent years, electronic devices have been required to be lighter and thinner and smaller. Therefore, in the electronic device casing used for the electronic device, there is a demand for a housing part having a thin thickness, a light weight, and a high rigidity.

  Among the electronic devices, terminal products that can be worn by human beings, so-called wearable terminals, have wires and parts mounted on a flexible material such as thin plastic film, rubber, and elastomer so that they can follow the movement of the body It is required to

  Furthermore, in order to further reduce the thickness and enhance the functionality of electronic devices that require a reduction in gaps of several tens of micrometers to several hundreds of micrometers, it is effective to integrate internal components and reduce the volume of components. . However, there are thermal limitations and layout restrictions for connecting with peripheral components, which is difficult to realize.

  Under such circumstances, it is possible to reduce the number of parts or perform an efficient layout by providing the function of the electric board, the antenna function, etc. to the electronic device casing which has conventionally been a simple cover part or appearance part. A technology for manufacturing a composite housing capable of

  On the other hand, as a technique for forming an electric circuit on a resin substrate, a technique for forming an electric circuit by a coating method such as inkjet or screen printing using a conductive ink instead of conventional photolithography has been proposed (for example, , Patent Documents 1 and 2). The formation of an electrical circuit by a coating method has attracted attention because it has the advantages of a short process and less waste as compared to photolithography. In these proposed techniques, it is necessary to bake the conductive ink at a low temperature from the viewpoint of the heat resistance of the resin substrate. Therefore, an ink receiving layer is provided on the substrate for the purpose of baking at a low temperature.

JP, 2010-010548, A International Publication WO 2013/015056 Pamphlet

  However, in the above-described proposed technology, it can not be said that the conductivity of the conductive layer formed by the conductive ink is sufficient. In the above-mentioned proposed technology, for example, the conductivity is improved by performing copper plating on the conductive layer formed of the conductive ink.

  This case makes it a subject to solve the said problems in the past, and to achieve the following objectives. That is, the present invention relates to a method of manufacturing a wiring structure capable of producing a wiring structure having a conductive layer excellent in conductivity and a wiring structure having a conductive layer excellent in conductivity with a short process and a small amount of waste. An object is to provide an electronic device having an excellent conductive layer.

The disclosed wiring structure is
Resin base material,
A cured layer containing a cured resin which is disposed on the resin base material and which is produced by the reaction of an acrylic polyol and an isocyanate curing agent.
A patterned conductive layer disposed on the cured layer and not mixed with at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin;
Have.

The disclosed electronic device is
With a plastic case,
A cured layer containing a cured resin, which is disposed on the resin case and formed by the reaction of an acrylic polyol and an isocyanate curing agent,
A patterned conductive layer disposed on the cured layer and not mixed with at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin;
Have.

The manufacturing method of the disclosed wiring structure is
A step of forming a cured layer containing a cured resin having a gel fraction of 90% by mass or more by applying a curable coating containing an acrylic polyol and an isocyanate curing agent onto a resin base and heating it. ,
After applying a conductive ink on the cured layer, the conductive ink is heated to form a patterned conductive layer;
including.

According to the disclosed wiring structure, a wiring structure having a conductive layer excellent in conductivity can be obtained.
According to the disclosed method for manufacturing a wiring structure, a wiring structure having a conductive layer excellent in conductivity can be manufactured in a short process and with less waste.
According to the disclosed electronic device, an electronic device having a conductive layer excellent in conductivity can be obtained.

FIG. 1A is a perspective view of a notebook computer which is an example of the disclosed electronic device. FIG. 1B is a partial cross-sectional view of FIG. 1A. FIG. 2A is a perspective view of a notebook computer as another example of the disclosed electronic device. FIG. 2B is a partial cross-sectional view of FIG. 2A. FIG. 3 is a rear view of a multifunctional mobile phone (smart phone) which is another example of the disclosed electronic device. FIG. 4 is a schematic cross-sectional view of the wiring structure in the case where the hardening of the hardened layer is insufficient in the hardened layer forming step. FIG. 5 is a schematic cross-sectional view of the wiring structure in the case where the hardening of the hardened layer is sufficient in the hardened layer forming step. FIG. 6 is a cross-sectional SEM photograph of the wiring structure of the fifth embodiment. FIG. 7 is a cross-sectional SEM photograph of the wiring structure of Comparative Example 1.

(Wiring structure and electronic equipment)
The disclosed wiring structure includes at least a resin base, a cured layer, and a conductive layer, and further includes other members as necessary.

  The disclosed electronic device includes at least a resin housing, a cured layer, and a conductive layer, and further includes other members as necessary.

<Resin base material and resin case>
There is no restriction | limiting in particular as a material of the said resin-made base materials and the said resin-made housings, According to the objective, it can select suitably, For example, a triacetyl cellulose (TAC), polyester (TPEE), a polyethylene terephthalate ( PET), polyethylene naphthalate (PEN), polyimide (PI), polyamide (PA), aramid, polyethylene (PE), polyacrylate, polyether sulfone, polysulfone, polypropylene (PP), polystyrene, diacetyl cellulose, polyvinyl chloride , Acrylic resin (PMMA), polycarbonate (PC), epoxy resin, urea resin, urethane resin, melamine resin, phenol resin, acrylonitrile butadiene styrene copolymer, cycloolefin polymer (COP), cycloolefin Nko polymer (COC), PC / PMMA laminate, such as rubber additives PMMA and the like.

  There is no restriction | limiting in particular as a shape of the said resin-made base materials and the said resin-made housing | casing, According to the objective, it can select suitably.

  A character, a pattern, an image, etc. may be printed on the surface of the resinous substrate and the resinous case. It is preferable that these are formed in the area | region where the said hardened layer and the said conductive layer are distribute | arranged.

<Hardened layer>
The cured layer is disposed on the resin base or the resin housing.
The cured layer contains at least a cured resin, preferably contains thermally conductive particles, and further contains other components as required.

  The cured layer may be formed on the resin base material, or a part of the resin case, or may be formed on the entire surface.

<< Curing resin >>
The cured resin is formed by the reaction of an acrylic polyol and an isocyanate curing agent.

-Acrylic polyol-
There is no restriction | limiting in particular as said acrylic polyol, if it is an acrylic resin which has several hydroxyl group, According to the objective, it can select suitably.

  The acrylic polyol can be synthesized, for example, by copolymerizing an acrylic monomer and a hydroxyl group-containing (meth) acrylic monomer.

Examples of the hydroxyl group-containing (meth) acrylic monomer include hydroxyalkyl (meth) acrylate. As said hydroxyalkyl (meth) acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, 1, 4- cyclohexanediol monoacrylate etc. are mentioned, for example.
The alkyl group of the hydroxyalkyl (meth) acrylate may be linear, branched or cyclic, preferably has 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms.

Examples of the acrylic monomer include (meth) acrylic acid and (meth) acrylic acid alkyl ester. Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid- n-butyl, isobutyl (meth) acrylate and the like can be mentioned.
These acrylic monomers may be used alone or in combination of two or more.

-Isocyanate curing agent-
The isocyanate curing agent is not particularly limited as long as it can react with the acrylic polyol to form the cured resin, and can be appropriately selected according to the purpose. For example, two or more in a molecule Polyvalent isocyanate which has an isocyanate group is mentioned.
As such polyvalent isocyanate, aromatic isocyanate, aliphatic (or alicyclic) isocyanate, etc. are mentioned, for example.
Examples of the aromatic isocyanate include xylylene diisocyanate and 4,4-diphenylmethane diisocyanate.
Examples of the aliphatic (or alicyclic) isocyanate include hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate and the like.
These isocyanate curing agents may be used alone or in combination of two or more.

  The isocyanate curing agent may be a blocked isocyanate in which an isocyanate group of a polyvalent isocyanate having two or more isocyanate groups in the molecule is blocked by a blocking agent.

  There is no restriction | limiting in particular as a ratio with the said acrylic polyol and the said isocyanate curing agent at the time of making the said acrylic polyol and the said isocyanate curing agent react, According to the objective, it can select suitably.

<< Thermally conductive particles >>
The thermally conductive particles are not particularly limited as long as they are particles having excellent thermal conductivity, and can be appropriately selected according to the purpose. Examples of the material include aluminum oxide, aluminum nitride, and aluminum hydroxide. Silicon oxide, boron nitride, titanium oxide, glass, zinc oxide, silicon carbide, silicon (silicon) and the like.
Among these, titanium oxide, silicon oxide, aluminum oxide and boron nitride are preferable in that they are both excellent in insulation and thermal conductivity.

  There is no restriction | limiting in particular as content of the said heat conductive particle in the said hardened layer, Although it can select suitably according to the objective, 40 mass%-60 mass% are preferable.

There is no restriction | limiting in particular as an average thickness of the said hardened layer, Although it can select suitably according to the objective, 1 micrometer-100 micrometers are preferable at the point which the said conductive layer which is excellent in conductivity is easy to obtain, 5 micrometers-80 micrometers More preferably, 10 μm to 70 μm is particularly preferable.
It is advantageous at the following points that the said average thickness is in the especially preferable range. The strength of the cured layer itself is excellent, the number of defects is small, and the adhesion to the resin base material is excellent. In addition, (1) the thermoplastic resin of the resin base material is prevented from being attacked directly by the solvent in the conductive ink when the conductive layer is formed, and (2) when the conductive layer is formed. A well-balanced cured layer can be obtained in three points of sufficient absorption of the organic component in the conductive ink and (3) excellent thermal conductivity.
On the other hand, if the average thickness of the cured layer is too thin, the strength of the cured layer may be weak and easily broken, and if the thickness is too thick, defects (such as cracks and bubbles upon drying) are easily generated. It may become easy to peel off due to the difference in expansion and contraction with the substrate and the difference in elongation.
In addition, the said average thickness is an average value at the time of measuring arbitrary ten places.

<Conductive layer>
The conductive layer is disposed on the hardened layer.
At least one of the acrylic polyol, the isocyanate curing agent, and the curing resin is not mixed in the conductive layer. When at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin is mixed in the conductive layer, the conductivity in the conductive layer is lowered.

  The shape of the conductive layer is not particularly limited as long as it has a pattern, and can be appropriately selected according to the purpose.

  The patterned conductive layer may be formed on a part or the whole of the cured layer.

  The patterned conductive layer preferably has a flat surface.

There is no restriction | limiting in particular as an electrical resistivity of the said conductive layer, Although it can select suitably according to the objective, It is preferable that it is less than 1.0x10 <^-7> ohm * m. There is no restriction | limiting in particular as a lower limit of the said electrical resistivity, Although it can select suitably according to the objective, 1.0 * 10 < ^-10 > ohm * m or more is preferable, and the said electrical resistivity is 1.0 × 10 ⁻⁹ Ω · m or more is more preferable.

  The conductive layer is preferably made of an aggregate of conductive particles. In other words, this means that the conductive layer is formed of a conductive ink. When the conductive layer is formed by a so-called dry method such as physical vapor deposition, chemical vapor deposition, or sputtering, conductive particles are not observed in the conductive layer. On the other hand, when the conductive layer is formed of a conductive ink, an aggregate in which conductive particles are aggregated is observed.

  There is no restriction | limiting in particular as a material of the said conductive layer, According to the objective, it can select suitably, For example, a transition metal etc. are mentioned. As the transition metal, an ionic transition metal is preferable. As such a transition metal, for example, copper, silver, gold, nickel, palladium, platinum, cobalt are preferable, and their electrical resistance is low and corrosion resistance is high. Silver, gold and copper are more preferable in that they can form a pattern.

There is no restriction | limiting in particular as an average thickness of the said conductive layer, Although it can select suitably according to the objective, 1 micrometer-100 micrometers are preferable, 5 micrometers-50 micrometers are more preferable, and 10 micrometers-30 micrometers are especially preferable. When forming the said conductive layer as the said average thickness is in a preferable range, it is easy to remove an organic component from a baking film, and can form the outstanding conductive layer. Therefore, the conductive layer can be formed at a lower temperature and in a short time.
The said average thickness is an average value at the time of measuring arbitrary ten places.

  The conductive layer plays a role of, for example, an antenna and other circuits.

  The interface between the conductive layer and the hardened layer is preferably flat in that the conductive layer having a uniform thickness can be obtained. Examples of a method of flattening the interface between the conductive layer and the hardened layer include a method of preventing the components of the hardened layer from being mixed into the conductive layer when forming the conductive layer, For example, the manufacturing method of the wiring structure of the indication disclosed later may be mentioned.

  There is no restriction | limiting in particular as said electronic device, According to the objective, it can select suitably, For example, a personal computer (notebook type personal computer, desktop type personal computer), a telephone, a mobile telephone, a copier, a facsimile, various printers, a digital camera Television, video, CD device, DVD device, air conditioner, remote control device, etc.

The wiring structure includes, for example, a semiconductor element, and is housed inside the electronic device.
As said semiconductor element, an integrated circuit, a large scale integrated circuit, a transistor, a thyristor, a diode, a solid-state image sensor etc. are mentioned, for example.

Here, an example of the disclosed electronic device is illustrated.
FIG. 1A is a perspective view of a notebook computer which is an example of the disclosed electronic device.
In the notebook personal computer shown in FIG. 1A, a conductive layer 3 in the form of a pattern is formed on the inside of the case via a hardened layer 2 as shown in FIG. 1B in a resin case 11 on the liquid crystal display side. There is. The patterned conductive layer 3 plays the role of an antenna.

Next, another example of the disclosed electronic device is illustrated.
FIG. 2A is a perspective view of a notebook computer as another example of the disclosed electronic device.
In the notebook personal computer shown in FIG. 2A, a conductive layer 3 in the form of a pattern is formed on the resin case 11 on the keyboard side via the hardened layer 2 as shown in FIG. 2B. The patterned conductive layer 3 plays a role of wiring that connects the sub display 4 and the semiconductor element that controls the sub display 4.

Next, another example of the disclosed electronic device is illustrated.
FIG. 3 is a rear view of a multifunctional mobile phone (smart phone) which is another example of the disclosed electronic device. The multifunction mobile phone shown in FIG. 3 has a CCD camera 5. The conductive layer 3 formed inside the resin casing 11 via the hardened layer plays a role of a wire connecting the CCD camera 5 and a semiconductor element that controls the CCD camera 5.

(Method of manufacturing wiring structure)
The manufacturing method of the disclosed wiring structure at least includes a hardened layer forming step and a conductive layer forming step, and further includes other steps as necessary.

<Hardened layer formation process>
In the step of forming a cured layer, the curable coating is applied on a resinous substrate and then heated to form a cured layer containing a cured resin having a gel fraction of 90% by mass or more. There is no particular limitation, and it can be selected appropriately according to the purpose.

  The curable coating contains an acrylic polyol and an isocyanate curing agent.

  In the method of manufacturing the disclosed wiring structure, the solvent of the conductive ink is absorbed by the cured layer when the conductive layer is formed by providing the cured layer. Therefore, the efficiency of firing of the conductive ink is increased, and a conductive layer having excellent conductivity can be formed as compared with the case where the cured layer is not provided.

However, when the conductive layer is formed in the conductive layer forming step, if the gel fraction of the cured resin of the cured layer is less than 90% by mass, the conductive layer may contain the acrylic polyol, the isocyanate curing agent, And at least one of the said hardening resin will be mixed in. As a result, the bonding state of the conductive particles in the conductive layer becomes insufficient, and the electrical resistivity of the conductive layer becomes high.
On the other hand, when the conductive layer is formed in the conductive layer forming step, when the gel fraction of the cured resin of the cured layer is 90% by mass or more, the acrylic polyol, the isocyanate curing agent, and the like in the conductive layer And at least one of the said cured resin will not be mixed in. As a result, the bonding state of the conductive particles in the conductive layer becomes sufficient, and the electrical resistivity of the conductive layer becomes low.

The above will be described using schematic diagrams (FIGS. 4 and 5).
FIG. 4 is a schematic cross-sectional view of the wiring structure in the case where the hardening of the hardened layer is insufficient in the hardened layer forming step.
When a conductive layer is formed using a conductive ink on the cured layer formed with the gel fraction of the cured resin being less than 90% by mass, part of the cured layer penetrates the conductive layer, as shown in FIG. Do. As a result, the bonding state of the conductive particles forming the conductive layer becomes insufficient, and the electrical resistivity of the conductive layer becomes high. In addition, when part of the hardened layer intrudes into the conductive layer, the interface between the hardened layer and the conductive layer becomes unclear, or as shown in FIG. 4, the interface becomes uneven.

FIG. 5 is a schematic cross-sectional view of the wiring structure in the case where the hardening of the hardened layer is sufficient in the hardened layer forming step.
When a conductive layer is formed using a conductive ink on the cured layer formed in a state where the gel fraction of the cured resin is 90 mass or more, as shown in FIG. 5, a part of the cured layer penetrates the conductive layer There is nothing to do. As a result, the bonding state of the conductive particles forming the conductive layer becomes sufficient, and the electrical resistivity of the conductive layer becomes low. In addition, since a part of the hardened layer does not penetrate into the conductive layer, the interface between the hardened layer and the conductive layer is clear, and as shown in FIG. 4, the interface is flat.

  In the hardened layer forming step, the hardened layer may be formed on a part of the resin base material or may be formed on the whole.

  There is no restriction | limiting in particular as said resin-made base materials, According to the objective, it can select suitably, For example, the said resin-made base materials etc. which were illustrated in description of the said wiring structure etc. are mentioned.

<< Curable paint >>
The curable coating is not particularly limited as long as it is a coating containing an acrylic polyol and an isocyanate curing agent, and can be appropriately selected according to the purpose. For example, a two-component acrylic urethane coating and the like can be mentioned. Be

  There is no restriction | limiting in particular as said acrylic polyol, According to the objective, it can select suitably, For example, the said acrylic polyol etc. which were illustrated in description of the said wiring structure are mentioned.

  There is no restriction | limiting in particular as said isocyanate hardening agent, According to the objective, it can select suitably, For example, the said isocyanate hardening agent illustrated in description of the said wiring structure etc. are mentioned.

It is preferable that the curable coating material further contains heat conductive particles in that the conductive layer having excellent conductivity can be formed in the conductive layer forming step.
There is no restriction | limiting in particular as said thermally conductive particle, According to the objective, it can select suitably, For example, the said thermally conductive particle etc. which were illustrated in description of the said wiring structure are mentioned.

  There is no restriction | limiting in particular as a method to apply | coat the said curable coating material on the said resin-made base materials, According to the objective, it can select suitably, For example, a bar coater method, a spray coat method, a curtain coat method, spin Coating methods, gravure coating methods, dipping methods and the like can be mentioned.

As a heating temperature at the time of heating after applying the said curable coating material on the said resin-made base materials, the said acrylic polyol and the said isocyanate curing agent react, and a gel fraction hardens 90 mass% or more There is no restriction | limiting in particular if it is temperature which resin is obtained, According to the objective, it can select suitably, For example, 100 degreeC-150 degreeC etc. are mentioned.
The acrylic polyol and the isocyanate curing agent react with each other as a heating time for heating after applying the curable coating on the resin base material, and curing with a gel fraction of 90% by mass or more There is no particular limitation as long as it is time to obtain a resin, and it can be selected appropriately according to the purpose.

  Here, the gel fraction of the cured resin in the cured layer can be determined by measuring acetone according to JIS K 6796 as an extraction solvent.

<Conductive layer forming process>
The conductive layer forming step is not particularly limited as long as it is a step of applying a conductive ink on the cured layer and then heating to form a conductive layer in a pattern shape, and it is appropriately selected according to the purpose. can do.

  In the conductive layer forming step, the conductive layer in a pattern may be formed on a part or all of the cured layer.

<< Conductive ink >>
The conductive ink contains at least a conductive substance, preferably contains a solvent, and further contains other components as required.

-Conductive substance-
Examples of the conductive substance include transition metals and compounds thereof. Among these, ionic transition metals are preferable, and as such a transition metal, copper, silver, gold, nickel, palladium, platinum, cobalt are preferable, the electric resistance is low, and a conductive pattern resistant to corrosion can be formed. In terms of point, silver, gold and copper are more preferable.

  As the conductive material, it is preferable to use a particulate material having an average particle diameter of about 1 nm to about 50 nm. In addition, the said average particle diameter means a center particle diameter (D50), and shows the value at the time of measuring with a laser diffraction scattering type particle size distribution measuring apparatus.

  There is no restriction | limiting in particular as content of the said conductive substance in the said conductive ink, Although it can select suitably according to the objective, 5 mass%-60 mass% are preferable, and 10 mass%-50 mass% More preferable.

-Solvent-
Examples of the solvent include organic solvents and water.

  The organic solvent is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include hydrocarbons such as tetradecane; cyclic hydrocarbons such as cyclohexane and cyclododecene; aromatic hydrocarbons such as toluene, xylene and mesitylene Etc. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as content of the said solvent in the said conductive ink, Although it can select suitably according to the objective, 35 mass%-90 mass% are preferable.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, the dispersing agent etc. which disperse | distribute the said electroconductive substance are mentioned.

Examples of the dispersant include amine-based polymer dispersants, hydrocarbon-based polymer dispersants having a carboxylic acid group in the molecule, and polymer dispersants having a polar group.
Examples of the amine-based polymer dispersant include polyethylene imine and polyvinyl pyrrolidone.
Examples of the hydrocarbon-based polymer dispersant having a carboxylic acid group in the molecule include polyacrylic acid and carboxymethyl cellulose.
Examples of the polymer dispersant having a polar group include polyvinyl alcohol, styrene-maleic acid copolymer, and olefin-maleic acid copolymer.

  There is no restriction | limiting in particular as a method of apply | coating the said conductive ink on the said cured layer, According to the objective, it can select suitably, For example, the screen-printing method, the roll coating method, the dip coating method, a spin coat method , An inkjet method, a nanoimprint method, and the like.

It is preferable to perform drying and baking after the said application.
The drying is not particularly limited as long as it can remove volatile components in the coating solution, and can be appropriately selected according to the purpose. In addition, in the said drying, it is not necessary to remove a volatile component completely, as long as a volatile component can be removed to such an extent that baking is not inhibited.
There is no restriction | limiting in particular as temperature of the said baking, if it is below the heat deformation temperature of the said resin-made base materials, although it can select suitably according to the objective, 100 degreeC-150 degreeC are preferable.
There is no restriction | limiting in particular as an atmosphere of the said baking, According to the objective, it can select suitably, For example, the atmosphere containing oxygen, such as oxygen and air, is mentioned. In addition, the atmosphere for firing may be an inert gas such as nitrogen gas.
There is no restriction | limiting in particular as time of the said baking, According to the objective, it can select suitably.

  The method of manufacturing the disclosed wiring structure can be suitably used for manufacturing the disclosed wiring structure.

  Examples of the disclosed technology will be described below, but the disclosed technology is not limited to the following examples.

<Resin base material>
In the following examples and comparative examples, polycarbonate (trade name: Iupilon, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) was used as a resin base material.

Example 1
<Manufacturing of wiring structure>
<< Formation of hardened layer >>
After spray coating a two-component acrylic urethane resin (trade name: Proquion, manufactured by Mikasa Paint Co., Ltd.) containing an acrylic polyol and an isocyanate curing agent onto the resin base material, it is applied at 70 ° C. for 50 minutes. It heated, and the average thickness obtained the hardened layer of 15 micrometers.

-Gel fraction-
The gel fraction of the cured resin in the cured layer was measured according to JIS K 6796 using acetone as an extraction solvent. The results are shown in Table 1-1.

-Resistance to ink solvents-
Decanol which is an ink solvent was dropped onto the cured layer, and the appearance of the cured layer was observed. The results are shown in Table 1-1.

<< Conductive layer formation >>
After screen printing (screen printing plate: 300 mesh) using silver paste (trade name: nano silver ink, manufactured by Harima Chemicals, Inc.) on the obtained cured layer, baking is performed at 130 ° C. for 2 hours, and width is obtained. A strip-shaped conductive layer (average thickness 20 μm) of 1 mm × 50 mm in length was formed.
Thus, the wiring structure was obtained.

<Measurement of electrical resistance>
The electrical resistance of the strip-like conductive layer was measured using a four-end needle measuring machine (trade name: Loresta, manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 1-1.

<Adhesiveness>
The adhesion of the strip-like conductive layer was measured by the 90 ° peeling method (JIS Z0237). The results are shown in Table 1-1.
In addition, it was set as the measurement result (N / 10 mm) by multiplying 10 times the measured value of the peeling test of the conductive layer of width 1 mm.

(Example 2)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the average thickness of the hardened layer in Example 1 was changed to 20 μm.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-1.

(Example 3)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the average thickness of the hardened layer was changed to 60 μm in Example 1.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-1.

(Example 4)
<Manufacturing of wiring structure>
In Example 1, at the time of formation of a hardened layer, titanium oxide (manufactured by Sakai Chemical Industry Co., Ltd., for paint) is used as a two-component acrylic urethane paint, and in the obtained hardened layer, the content of titanium oxide is 50 mass A wiring structure was manufactured in the same manner as in Example 1 except that the composition was formulated to be in%.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-1.

(Example 5)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the formation of the hardened layer in Example 1 was replaced by the following method.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-1.

<< Formation of hardened layer >>
After spray coating a two-component acrylic urethane resin (trade name: Air Urethane, manufactured by Isam Paint Co., Ltd.) containing an acrylic polyol and an isocyanate curing agent onto the resinous substrate, 60 ° C. at 70 ° C. Heating was performed for a minute to obtain a cured layer having an average thickness of 25 μm.

The cross-sectional SEM photograph of the obtained wiring structure is shown in FIG.
Since curing of the cured layer before forming the conductive layer is sufficient, the interface A between the cured layer and the conductive layer is clear and flat.

(Comparative example 1)
<Manufacturing of wiring structure>
<< Formation of hardened layer >>
After spray coating a two-component acrylic urethane coating (trade name: Air Urethane, manufactured by Isam Coatings Co., Ltd.) containing an acrylic polyol and an isocyanate curing agent onto the resin base material, 10 at 70 ° C. Drying for a minute gave an uncured layer having an average thickness of 25 μm.

<< Conductive layer formation >>
After screen printing (screen printing plate: 300 mesh) using silver paste (trade name: nano silver ink, manufactured by Harima Chemicals, Inc.) on the obtained uncured layer, baking is performed at 130 ° C. for 2 hours, The uncured layer was cured, and a strip-like conductive layer (average thickness 20 μm) of 1 mm wide × 50 mm long was formed.
Thus, the wiring structure was obtained.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-2.

The cross-sectional SEM photograph of the obtained wiring structure is shown in FIG.
Since curing of the cured layer before forming the conductive layer is insufficient, part of the cured layer penetrates the conductive layer, and the interface A is not flat.

(Comparative example 2)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the formation of the hardened layer in Example 1 was replaced with the formation of the following resin layer.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-2.

<< Formation of resin layer >>
After one-component acrylic urethane paint (trade name: Acrit, manufactured by Taisei Fine Chemical Co., Ltd.) was brush-coated on the resin base, it was dried at 100 ° C. for 10 minutes to obtain a resin layer having an average thickness of 15 μm. .

(Comparative example 3)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the formation of the hardened layer in Example 1 was replaced with the formation of the following resin layer.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-2.

<< Formation of resin layer >>
After one-component acrylic lacquer (trade name: acrylic lacquer, manufactured by Nippone Products Co., Ltd.) is spray-coated on the resin base, it is dried at 70 ° C. for 30 minutes to obtain a resin layer having an average thickness of 20 μm. The

(Comparative example 4)
<Manufacturing of wiring structure>
After screen printing (screen printing plate: 300 mesh) using silver paste (trade name: nano silver ink, manufactured by Harima Chemicals, Inc.) on a resin base material, baking is performed at 130 ° C. for 2 hours, and the width is 1 mm X A 50 mm long strip-like conductive layer (average thickness 20 μm) was formed.
Thus, the wiring structure was obtained.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-2.

(Comparative example 5)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the formation of the hardened layer in Example 1 was replaced by the following method.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-2.

<< Formation of hardened layer >>
After spray coating a two-component polyurethane resin paint (trade name: Polyphen # 21, manufactured by Shoko Co., Ltd. stock company) using polyester polyol onto the resin base, it is heated at 80 ° C. for 50 minutes , A cured layer having an average thickness of 25 μm was obtained.

(Comparative example 6)
<Manufacturing of wiring structure>
A wiring structure was manufactured in the same manner as in Example 1 except that the formation of the hardened layer in Example 1 was replaced by the following method.
Evaluation similar to Example 1 was performed about the obtained wiring structure. The results are shown in Table 1-2.

<< Formation of hardened layer >>
A two-component polyurethane resin paint (trade name: Esco LTC, manufactured by Kansai Paint Co., Ltd.) using an epoxy polyol resin is spray-coated on the resin base, and then heated at 80 ° C. for 50 minutes. A hardened layer with a thickness of 30 μm was obtained.

Here, in Tables 1-1 and 1-2, “E” in the electrical resistivity means a power of 10, for example, “E-08” means “× 10 ⁻⁸ ”.

  In Examples 1 to 5, the conductive layer is formed on the cured layer having a cured resin obtained by sufficiently reacting the acrylic polyol and the isocyanate curing agent. Therefore, in the conductive layer, at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin was not mixed, and a conductive layer having excellent conductivity was obtained. Moreover, when the surface was rubbed using decanol which is an ink solvent, the metal film did not melt | dissolve in the conductive layer obtained in Examples 1-5.

  On the other hand, in Comparative Example 1, the cured layer has a cured resin obtained by reacting an acrylic polyol and an isocyanate curing agent, but the reaction does not proceed sufficiently. Therefore, when the conductive layer is formed on the cured layer, at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin is mixed into the conductive layer, and the conductivity of the conductive layer is lowered. did. Moreover, when the surface was rubbed using decanol which is an ink solvent, in the conductive layer obtained in Comparative Example 1, the metal film was dissolved.

  In Comparative Examples 2 to 6, the conductivity of the conductive layer decreased because the cured layer did not have a cured resin obtained by the reaction of the acrylic polyol and the isocyanate curing agent. Moreover, when the surface was rubbed using the ink solvent which is an ink solvent, the metal film melt | dissolved the conductive layer obtained by Comparative Example 2-6.

Further, the following appendices will be disclosed regarding the above embodiment.
(Supplementary Note 1)
Resin base material,
A cured layer containing a cured resin which is disposed on the resin base material and which is produced by the reaction of an acrylic polyol and an isocyanate curing agent.
A patterned conductive layer disposed on the cured layer and not mixed with at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin;
Wiring structure characterized by having.
(Supplementary Note 2)
The wiring structure according to appendix 1, wherein the electrical resistivity of the conductive layer is less than 1.0 × 10 ⁻⁷ Ω · m.
(Supplementary Note 3)
The wiring structure according to any one of Appendices 1 to 2, wherein the hardened layer contains heat conductive particles.
(Supplementary Note 4)
The wiring structure according to any one of appendices 1 to 3, wherein the conductive layer is an aggregate of conductive particles.
(Supplementary Note 5)
With a plastic case,
A cured layer containing a cured resin, which is disposed on the resin case and formed by the reaction of an acrylic polyol and an isocyanate curing agent,
A patterned conductive layer disposed on the cured layer and not mixed with at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin;
Electronic equipment characterized by having.
(Supplementary Note 6)
The electronic device according to appendix 5, wherein the electrical resistivity of the conductive layer is less than 1.0 × 10 ⁻⁷ Ω · cm.
(Appendix 7)
The electronic device according to any one of appendices 5 to 6, wherein the hardened layer contains heat conductive particles.
(Supplementary Note 8)
The electronic device according to any one of appendices 5 to 7, wherein the conductive layer is an aggregate of conductive particles.
(Appendix 9)
A step of forming a cured layer containing a cured resin having a gel fraction of 90% by mass or more by applying a curable coating containing an acrylic polyol and an isocyanate curing agent onto a resin base and heating it. ,
After applying a conductive ink on the cured layer, the conductive ink is heated to form a patterned conductive layer;
A method of manufacturing a wiring structure comprising:
(Supplementary Note 10)
15. The method for producing a wiring structure according to appendix 9, wherein the curable paint further contains thermally conductive particles.

1 resin base material 2 hardened layer 3 conductive layer 4 sub display 5 CCD camera 11 resin case

Claims (12)

Resin base material,
A cured layer containing a cured resin which is disposed on the resin base material and which is produced by the reaction of an acrylic polyol and an isocyanate curing agent.
A patterned conductive layer disposed on the cured layer and not mixed with at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin;
I have a,
The hardened layer contains heat conductive particles,
Wiring structure content of the thermally conductive particles, characterized by 40% to 60% by mass Rukoto in the cured layer. The wiring structure according to claim 1, wherein the electrical resistivity of the conductive layer is less than 1.0 × 10 ⁻⁷ Ω · m. The wiring structure according to any one of claims 1 to 2, wherein the thermally conductive particles contain at least one of titanium oxide, silicon oxide, aluminum oxide and boron nitride. The wiring structure according to any one of claims 1 to 3, wherein the conductive layer comprises an aggregate of conductive particles. With a plastic case,
A cured layer containing a cured resin, which is disposed on the resin case and formed by the reaction of an acrylic polyol and an isocyanate curing agent,
A patterned conductive layer disposed on the cured layer and not mixed with at least one of the acrylic polyol, the isocyanate curing agent, and the cured resin;
Have
The hardened layer contains heat conductive particles,
Content of the said heat conductive particle in the said hardened layer is 40 mass%-60 mass%, The electronic device characterized by the above-mentioned. The electrical resistivity of the conductive layer is 1.0 × 10 ^-7 The electronic device according to claim 5, which is less than Ω · m. The electronic device according to any one of claims 5 to 6, wherein the thermally conductive particles contain at least one of titanium oxide, silicon oxide, aluminum oxide and boron nitride. The electronic device according to any one of claims 5 to 7, wherein the conductive layer comprises an aggregate of conductive particles. A step of forming a cured layer containing a cured resin having a gel fraction of 90% by mass or more by applying a curable coating containing an acrylic polyol and an isocyanate curing agent onto a resin base and heating it. ,
After applying a conductive ink on the cured layer, the conductive ink is heated to form a patterned conductive layer;
A method of manufacturing a wiring structure comprising: The method for producing a wiring structure according to claim 9, wherein the curable paint further contains heat conductive particles. The method for manufacturing a wiring structure according to claim 10, wherein the thermally conductive particles contain at least one of titanium oxide, silicon oxide, aluminum oxide, and boron nitride. The method for manufacturing a wiring structure according to any one of claims 10 to 11, wherein a content of the thermally conductive particles in the hardened layer is 40% by mass to 60% by mass.