JP2016131000A - Conductive pattern-formed sheet and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a conductive pattern-formed sheet that can easily form an electrode wiring having each different pattern from each other on one surface and the other surface of a base material and can further enhance accuracy of the electrode wiring.SOLUTION: A manufacturing method of a conductive pattern-formed sheet 1 according to the present invention comprises: a first metal layer forming step of vapor-depositing a long wavelength-absorbent metal on one surface of a base material 10 to form a first metal layer; a second metal layer forming step of vapor-depositing a short wavelength-absorbent metal on the other surface of the base material 10 to form a second metal layer; a first electrode wiring forming step of dry-etching the first metal layer by irradiating the first metal layer with a long wavelength laser beam having a wavelength of 1064 nm in a pattern shape to form a first electrode wiring 20; and a second electrode wiring forming step of dry-etching the second metal layer by irradiating the second metal layer with a short wavelength laser beam having a wavelength of 355 nm or a wavelength of 532 nm in a pattern shape to form a second electrode wiring 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive pattern forming sheet and a manufacturing method thereof.

In recent years, capacitive touch panels or capacitive touch sensors have been widely used as input devices in electronic devices such as personal computers, portable terminals, game machines, and office office equipment.
Conventionally, in a capacitive touch panel, a capacitive touch sensor, etc., a sensor obtained by bonding two conductive pattern forming sheets having a conductive pattern formed on one side of a base material using a double-sided adhesive film or the like. (Patent Document 1).

  In recent years, further reduction in thickness and cost have been demanded in electronic devices equipped with a capacitive touch panel or a capacitive touch sensor. In response to this requirement, it is conceivable to form electrode wiring on both surfaces of the base material as in the sensor sheet described in Patent Document 2. However, in this case, the pattern of the electrode wiring on one side and the pattern of the electrode wiring on the other side must be different. In order to make the pattern of the electrode wiring on one side different from the pattern of the electrode wiring on the other side, a complicated method must be applied, and the accuracy of the electrode wiring may be lowered. .

JP 2012-3402 JP 2012-33343 A

  It is an object of the present invention to provide a conductive pattern forming sheet that can easily form electrode wirings having different patterns on one surface and the other surface of a base material and that has high electrode wiring accuracy, and a method for manufacturing the same. And

The present invention has the following aspects.
The conductive pattern forming sheet of the present invention includes a base material, a first electrode wiring composed of a first metal layer formed on one surface of the base material, and a second metal formed on the other surface of the base material. A second electrode wiring comprising a layer,
The first electrode wiring and the second electrode wiring have different patterns, and the metal constituting the first metal layer has an absorptivity of a long wavelength laser beam having a wavelength of 1064 nm of 15% or more and a wavelength. An absorptivity of a short wavelength laser beam having a wavelength of 355 nm or a wavelength of 532 nm is a long wavelength absorbing metal having an absorptivity of a short wavelength laser beam of 355 nm or a wavelength of 532 nm of less than 60%. Is a short-wavelength absorptive metal having a long-wavelength laser light absorption of less than 15%.
In the conductive pattern forming sheet of the present invention, it is preferable that both the first metal layer and the second metal layer have a thickness of 0.01 to 1.0 μm.

In the method for producing a conductive pattern forming sheet of the present invention, the absorption rate of a long wavelength laser beam having a wavelength of 1064 nm is 15% or more and the absorption rate of a short wavelength laser beam having a wavelength of 355 nm or 532 nm on one surface of a substrate. A first metal layer forming step of forming a first metal layer by vapor-depositing a long-wavelength absorbing metal having a thickness of less than 60%;
The short-wavelength absorptive metal having an absorptivity of short-wavelength laser light having a wavelength of 355 nm or 532 nm and a long-wavelength laser light having a wavelength of 1064 nm of less than 15% on the other surface of the base material A second metal layer forming step of forming a second metal layer by evaporating
A first electrode wiring forming step of forming a first electrode wiring by dry etching the first metal layer by irradiating the first metal layer with a long wavelength laser beam having a wavelength of 1064 nm in a pattern;
Irradiating the second metal layer with a short wavelength laser beam having a wavelength of 355 nm or a wavelength of 532 nm in a pattern to dry-etch the second metal layer to form a second electrode wiring; and Have.
In the method for producing a conductive pattern forming sheet of the present invention, in the first metal layer forming step, the thickness of the first metal layer is set to 0.01 to 1.0 μm, and in the second metal layer forming step, the second metal layer is formed. It is preferable that the thickness of the metal layer be 0.01 to 1.0 μm.

The conductive pattern forming sheet of the present invention can easily form electrode wirings having different patterns on one surface and the other surface of the substrate, and the electrode wiring accuracy is high.
According to the method for producing a conductive pattern forming sheet of the present invention, electrode wirings having different patterns can be easily formed on one surface and the other surface of the substrate, and the accuracy of the electrode wiring can be increased.

It is a top view which shows one side of the conductive pattern formation sheet in one Embodiment of this invention. It is a top view which shows the other surface of the conductive pattern formation sheet in one Embodiment of this invention. It is I-I 'sectional drawing of FIG. It is II-II 'sectional drawing of FIG. It is sectional drawing explaining the 1st metal layer formation process in one Embodiment of this invention. It is sectional drawing explaining the 2nd metal layer formation process in one Embodiment of this invention. It is sectional drawing explaining the 1st electrode wiring formation process in one Embodiment of this invention. It is sectional drawing explaining the 2nd electrode wiring formation process in one Embodiment of this invention.

<Conductive pattern forming sheet>
An embodiment of the conductive pattern forming sheet of the present invention will be described.
The conductive pattern formation sheet of this embodiment is shown in FIGS. The conductive pattern forming sheet 1 of the present embodiment includes a base material 10, a first electrode wiring 20 formed on one surface (first surface 10a) of the base material 10, and the other surface (second surface) of the base material 10. And a second electrode wiring 30 formed on the surface 10b). A first external connection terminal 40 a is provided on the first surface 10 a of the base material 10, and a second external connection terminal 40 b is provided on the second surface 10 b of the base material 10. A first insulating layer 50a is formed so as to cover the first surface 10a of the substrate 10, the first electrode wiring 20, and a part of the first external connection terminal 40a, and the second surface 10b of the substrate 10 and the second surface 10b. A second insulating layer 50b is formed so as to cover the electrode wiring 30 and a part of the second external connection terminal 40b.
In this specification, “conductive” means that the electric resistance value is less than 1 MΩ, and “insulation” means that the electric resistance value is 1 MΩ or more, preferably 10 MΩ or more.

(Base material)
As the substrate 10, a plastic film or a glass plate can be used, and it is preferable that the substrate 10 is transparent. As the transparent resin constituting the transparent plastic film, polyethylene terephthalate, polycarbonate, polyimide, triacetyl cellulose, cyclic polyolefin, acrylic resin, and the like can be used. Among these, polyethylene terephthalate or polycarbonate is preferable because of its high heat resistance and dimensional stability and low cost. “Transparent” means that the light transmittance measured according to JIS K7136 is 50% or more.
The surface of the substrate 10 may be subjected to various surface treatments such as plasma treatment, ultraviolet irradiation treatment, corona treatment, and excimer light treatment. When the surface treatment is performed on the base material 10, the adhesion between the first electrode wiring 20 and the second electrode wiring 30 is improved.
The thickness of the substrate 10 is preferably 25 to 75 μm. If the thickness of the substrate 10 is equal to or greater than the lower limit value, it is difficult to break during processing, and if the thickness is equal to or less than the upper limit value, the conductive pattern forming sheet 1 can be made thinner and can be easily used after being folded. .

(First electrode wiring)
The 1st electrode wiring 20 is a wiring used as an electrode, and consists of a 1st metal layer formed in pattern shape. The first electrode wiring 20 in the present embodiment includes a plurality of Y-direction electrode portions 21 formed along the Y direction and the Y-direction electrode portions 21 for electrically connecting the first external connection terminal 40a. It consists of the first routing wiring 22. The Y-direction electrode portion 21 in the present embodiment is a linear electrode portion having a constant width.
The metal constituting the first metal layer has a long-wavelength absorptivity in which a long-wavelength laser light having a wavelength of 1064 nm has an absorptance of 15% or more and a short-wavelength laser light having a wavelength of 355 nm or a wavelength of 532 nm is less than 60%. It is a metal. Specific examples of the long wavelength absorbing metal include nickel and aluminum.
When the absorption rate of the short wavelength laser beam of the metal constituting the first metal layer is 60% or more or the absorption rate of the long wavelength laser beam is less than 15%, the first electrode wiring and the second electrode wiring having different patterns are arranged. It becomes difficult to form.

  The thickness (average value) of the first metal layer is preferably 0.01 to 1.0 μm, and more preferably 0.05 to 0.3 μm. If the thickness of the first metal layer is equal to or greater than the lower limit value, the electrical resistance of the wiring can be sufficiently reduced, and if the thickness is equal to or less than the upper limit value, disconnection when the conductive pattern forming sheet is bent can be prevented.

(Second electrode wiring)
The 2nd electrode wiring 30 is a wiring used as an electrode, and consists of a 2nd metal layer formed in pattern shape. The second electrode wiring 30 in the present embodiment includes a plurality of X-direction electrode portions 31 formed along the X direction, and electrically connects the X-direction electrode portions 31 to the second external connection terminal 40b. It consists of the second routing wiring 32. Therefore, the pattern of the second electrode wiring 30 is different from the pattern of the first electrode wiring 20.
The metal constituting the second metal layer has a short wavelength absorptivity in which an absorptivity of a short wavelength laser beam having a wavelength of 355 nm or a wavelength of 532 nm is 35% or more and an absorptance of a long wavelength laser beam having a wavelength of 1064 nm is less than 15%. It is a metal. Specific examples of the short wavelength absorbing metal include copper and silver.
When the absorptivity of the short wavelength laser light of the metal constituting the second metal layer is less than 35% or the absorptance of the long wavelength laser light is 15% or more, the first electrode wiring 20 and the second electrode wiring having different patterns from each other 30 becomes difficult to form.

  The thickness (average value) of the second metal layer is preferably 0.01 to 1.0 μm, and more preferably 0.05 to 0.3 μm. If the thickness of the first metal layer is equal to or greater than the lower limit value, the electrical resistance of the wiring can be sufficiently reduced, and if the thickness is equal to or less than the upper limit value, disconnection when the conductive pattern forming sheet is bent can be prevented.

(First external connection terminal, second external connection terminal)
The first external connection terminal 40a and the second external connection terminal 40b are terminals for connecting to an external circuit, and are made of a conductive material such as metal or carbon. The first external connection terminal 40a and the second external connection terminal 40b are rectangular conductive portions, and a part thereof is not covered with the first insulating layer 50a or the second insulating layer 50b and is exposed. doing. The exposed part is connected to an external element or circuit.

(First insulating layer, second insulating layer)
An insulating resin is used as the resin for forming the first insulating layer 50a and the second insulating layer 50b. As the insulating resin, a thermosetting resin or an ultraviolet curable resin is used, but an ultraviolet curable resin is preferable because of its low thermal shrinkage during curing.
The thicknesses of the first insulating layer 50a and the second insulating layer 50b are preferably thin as long as the insulating property can be secured in order to reduce the thickness of the conductive pattern forming sheet, and specifically, 0.5 to 25 μm. It is preferable.

<Method for producing conductive pattern forming sheet>
Hereinafter, a method for producing the conductive pattern forming sheet 1 will be described.
The manufacturing method of the conductive pattern forming sheet of this embodiment includes a first metal layer forming step, a second metal layer forming step, a first electrode wiring forming step, a second electrode wiring forming step, and a first external connection. A terminal forming step, a first insulating layer forming step, a second external connection terminal forming step, and a second insulating layer forming step.

(First metal layer forming step)
The first metal layer forming step is a step of forming a first metal layer 20a by depositing a long wavelength absorbing metal on the first surface 10a of the base material 10 (see FIG. 5).
The metal vapor deposition method for depositing the long wavelength absorbing metal on the substrate is not particularly limited. For example, plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, vacuum deposition method, sputtering. Method, reactive sputtering method, MBE (molecular beam epitaxy) method, cluster ion beam method, ion plating method, plasma polymerization method (high frequency excitation ion plating method), and the like. Among these, the vacuum deposition method is preferable because the film forming speed is high and the cost is low.
In the first metal layer forming step, the thickness of the first metal layer 20a is preferably 0.01 to 1.0 μm, and preferably 0.05 to 0.3 μm.
When the vacuum deposition method is applied, examples of the method for adjusting the thickness of the first metal layer 20a include a method of adjusting the deposition time according to the conveyance speed of the base material 10 when the metal is deposited.

(Second metal layer forming step)
The second metal layer forming step is a step of forming a second metal layer 30a by depositing a short wavelength absorbing metal on the second surface 10b of the substrate 10 (see FIG. 6).
The metal vapor deposition method for depositing the short wavelength absorbing metal on the substrate is not particularly limited, and is the same as the metal vapor deposition method in the first metal layer forming step.

(First electrode wiring forming step)
The first electrode wiring forming step, by irradiating a long-wavelength laser light L ₁ in a pattern on the first metal layer 20a, the first metal layer 20a is a step of forming a first electrode wiring by dry etching ( (See FIG. 7). Specifically, first, after the first metal layer 20a is arranged on the upper side of the substrate 10, a portion of the first metal layer 20a that does not become the first electrode wiring (that is, the Y-direction electrode portion and the first routing wiring). in dry etched by irradiating the long-wavelength laser light L _1. Long wavelength laser L ₁ is preferably directly irradiated to the first metal layer 20a.
The long-wavelength wavelength of the laser beam _{L 1,} it is possible to apply the 1064 nm. The output of long wavelength laser light _{L 1} is preferably to 1～5W, it is more preferable to 2～4W. Scanning speed of the long-wavelength laser light _{L 1} is preferably set to 100~8000mm / s, and more preferably in 250~1500mm / s. Frequency of long-wavelength laser light _{L 1} is preferably set to 20～1000KHz, it is more preferable to 100～300KHz.

(Second electrode wiring formation step)
The second electrode wiring forming step, by irradiating short-wavelength laser beam L ₂ in a pattern on the second metal layer 30a, the second metal layer 30a is a step of forming a second electrode wiring by dry etching ( (See FIG. 8). Specifically, after the second metal layer 30a is turned upside down so that the second metal layer 30a is disposed on the upper side of the base material 10, the second electrode wiring (that is, the X-direction electrode portion and the second routing) of the second metal layer 30a. the portion not in line), dry etching by irradiating short-wavelength laser beam L _2. Short wavelength laser L ₂ is preferably irradiated directly to the second metal layer.
The wavelength of the short wavelength laser beam _{L 2,} can be applied 355nm or 532 nm.
The output of the short wavelength laser beam _{L 2} is preferably to 1～5W, it is more preferable to 2～4W. The scanning speed of the short-wavelength laser beam _{L 2} is preferably set to 100~8000mm / s, and more preferably in 250~1500mm / s. The frequency of the short-wavelength laser beam _{L 2} is preferably set to 20～1000KHz, it is more preferable to 100～300KHz.

(First external connection terminal forming step)
The first external connection terminal forming step is a step of forming the first external connection terminal 40 a on the first surface 10 a of the substrate 10 so as to be in contact with the end portion of the first routing wiring 22. As a method of forming the first external connection terminal 40a, for example, a method of screen printing a conductive paste can be cited.

(First insulating layer forming step)
In the first insulating layer forming step, the first surface 10a of the substrate 10 is covered with the first surface 10a of the substrate 10, the first electrode wiring 20, and a part of the first external connection terminal 40a. This is a step of forming one insulating layer 50a.
Examples of the method for forming the first insulating layer 50a include a method of printing or applying a first insulating layer forming ink containing an insulating resin.
As a printing method of the first insulating layer forming ink, screen printing or inkjet printing can be applied. Screen printing is preferable in that the printing speed is fast, and ink jet printing is preferable in that the first insulating layer 50a can be thinned. The first insulating layer forming ink may be printed once or a plurality of times.
After printing, after drying as necessary, if a thermosetting resin is used as the insulating resin, the printed ink is heated and cured, and an ultraviolet curable resin is used as the insulating resin. Irradiates the printed ink with ultraviolet rays to cure the ink.

(Second external connection terminal forming step)
The second external connection terminal forming step is a step of forming the second external connection terminal 40b on the second surface 10b of the substrate 10 so as to be in contact with the end portion of the first routing wiring 32. As a method of forming the second external connection terminal 40b, for example, a method of screen printing a conductive paste can be cited.

(Second insulating layer forming step)
In the second insulating layer forming step, the second surface 10b of the base material 10, the second electrode wiring 30, and a part of the second external connection terminal 40b are covered on the second surface 10b side of the base material 10. This is a step of forming two insulating layers 50b.
The formation method of the second insulating layer 50b is the same as the first insulating layer forming step except that the second insulating layer forming ink containing an insulating resin is used instead of the first insulating layer forming ink.
The insulating resin contained in the second insulating layer forming ink may be the same as or different from the insulating resin contained in the first insulating layer forming ink.

(Function and effect)
When the first metal layer formed on the first surface of the base material and the second metal layer formed on the second surface of the base material are composed of the same metal, etching is performed by irradiating one metal layer with laser light. Then, the other metal layer is also etched by the laser beam. Therefore, it is difficult to make the pattern of the first electrode wiring and the pattern of the second electrode wiring different from each other.
In the present embodiment, the first metal layer 20a formed on the first surface 10a of the base material 10 is a layer composed of a long wavelength absorbing metal, and the second metal layer 30a formed on the second surface 10b of the base material 10 is formed. The layer is composed of a short wavelength absorbing metal.
As shown in FIG. 7, when irradiated with long-wavelength laser light L ₁ to the first metal layer 20a, it absorbs long-wavelength laser light L ₁ at the laser beam irradiated portion of the first metal layer 20a, the light energy Is converted into heat. Therefore, the laser light irradiated portion of the first metal layer 20a is sublimated and removed by the generated heat. Even long wavelength laser light L ₁ which is not absorbed by the first metal layer 20a has reached the second metal layer 30a through the substrate, the second metal layer 30a is less likely to absorb long-wavelength laser light L ₁ Therefore, sublimation hardly occurs.
On the other hand, as shown in FIG. 8, when irradiated with short-wavelength laser beam L ₂ to the second metal layer 30a absorbs the short wavelength laser beam L ₂ in the laser beam irradiated portion of the second metal layer 30a, the Light energy is converted to heat. Therefore, the laser beam irradiated portion of the second metal layer 30a is sublimated and removed by the generated heat. Even short-wavelength laser light L ₂ which is not absorbed by the second metal layer 30a has reached the first metal layer 20a through the substrate, the first metal layer 20a is hard to absorb short-wavelength laser beam L ₂ Therefore, sublimation hardly occurs.
Therefore, only the first metal layer 20a by irradiating a long-wavelength laser light L ₁ to the first metal layer 20a selectively can form an etching to the first electrode wiring 20, a short wavelength laser in the second metal layer 30a only the second metal layer 30a by irradiating the light L ₂ to be formed is selectively etched to the second electrode wiring 30.
As described above, in the manufacturing method according to the present embodiment, the first surface 10a and the second surface 10 of the substrate 10 are selectively used by properly using the laser light applied to the first metal layer 20a and the laser light applied to the second metal layer 30a. Electrode wirings having different patterns can be easily formed on the surface 10b.
In addition, since the first metal layer 20a and the second metal layer 30a can be selectively etched, the first metal layer 20a and the second metal layer 30a are not etched at the same time. Get higher.
In addition, the conductive pattern forming sheet 1 is thinned because electrode wiring is formed on both surfaces of the substrate 10.

In addition, this invention is not limited to the said embodiment.
For example, the first electrode wiring and the second electrode wiring do not need to be those of the above embodiment. For example, the X-direction electrode portion and the Y-direction electrode portion do not have to have a constant width, and may have a shape in which a plurality of quadrangles are connected, a semicircle, or a shape in which circles are connected in plan view.
Further, the first electrode wiring and the second electrode wiring do not need to include the lead wiring. When the first electrode wiring and the second electrode wiring do not include the routing wiring, the routing wiring may be formed by printing a conductive paste.
In addition, the first external connection terminal, the second external connection terminal, the first insulating layer, and the second insulating layer are preferably formed, but this is not an essential configuration.
In the manufacturing method in the above embodiment, the second metal layer forming step is performed after the first metal layer forming step. However, the first metal layer forming step may be performed after the second metal layer forming step. Moreover, in the manufacturing method in the said embodiment, although the 2nd electrode wiring formation process was performed after the 1st electrode wiring formation process, you may perform a 1st electrode wiring formation process after a 2nd electrode wiring formation process.

  The conductive pattern forming sheet of the present invention can be suitably used for a capacitive touch panel and a capacitive touch pad.

DESCRIPTION OF SYMBOLS 1 Conductive pattern formation sheet 10 Base material 20 1st electrode wiring 20a 1st metal layer 21 Y direction electrode part 22 1st routing wiring 30 2nd electrode wiring 30a 2nd metal layer 31 X direction electrode part 32 2nd routing wiring 40a 1st 1 external connection terminal 40b second external connection terminal 50a first insulating layer 50b second insulating layer L ₁ long wavelength laser light L ₂ short wavelength laser light

Claims (4)

A base material, a first electrode wiring made of a first metal layer formed on one surface of the base material, and a second electrode wiring made of a second metal layer formed on the other surface of the base material. Prepared,
The first electrode wiring and the second electrode wiring have different patterns, and the metal constituting the first metal layer has an absorptivity of a long wavelength laser beam having a wavelength of 1064 nm of 15% or more and a wavelength. An absorptivity of a short wavelength laser beam having a wavelength of 355 nm or a wavelength of 532 nm is a long wavelength absorbing metal having an absorptivity of a short wavelength laser beam of 355 nm or a wavelength of 532 nm of less than 60%. A conductive pattern forming sheet, which is a short wavelength absorptive metal having a long wavelength laser beam with a wavelength of 1064 nm of less than 15%.   The conductive pattern forming sheet according to claim 1, wherein both the first metal layer and the second metal layer have a thickness of 0.01 to 1.0 μm. A long wavelength absorptive metal having an absorptivity of a long wavelength laser beam having a wavelength of 1064 nm of 15% or more and an absorptivity of a short wavelength laser beam having a wavelength of 355 nm or 532 nm is less than 60% on one surface of the substrate. A first metal layer forming step of forming a first metal layer by vapor deposition;
The short-wavelength absorptive metal having an absorptivity of short-wavelength laser light having a wavelength of 355 nm or 532 nm and a long-wavelength laser light having a wavelength of 1064 nm of less than 15% on the other surface of the base material A second metal layer forming step of forming a second metal layer by evaporating
A first electrode wiring forming step of forming a first electrode wiring by dry etching the first metal layer by irradiating the first metal layer with a long wavelength laser beam having a wavelength of 1064 nm in a pattern;
Irradiating the second metal layer with a short wavelength laser beam having a wavelength of 355 nm or a wavelength of 532 nm in a pattern to dry-etch the second metal layer to form a second electrode wiring; and A method for producing a conductive pattern forming sheet.   In the first metal layer forming step, the thickness of the first metal layer is set to 0.01 to 1.0 μm, and in the second metal layer forming step, the thickness of the second metal layer is set to 0.01 to 1.0 μm. The manufacturing method of the conductive pattern formation sheet of Claim 3.

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