JP7034853B2 - Method of manufacturing conductive sheet - Google Patents

Description

The present invention relates to a conductive sheet, and more particularly to a method for manufacturing a conductive sheet having through holes filled with a conductive material.

Conventionally, there is a method in which a through hole is formed in a base material and filled with a conductive paste to electrically connect the conductive layers formed on both the front and back surfaces of the base material.

In the conductive layer pattern forming apparatus described in Patent Document 1, when the via hole of the green sheet is filled with the conductor paste, the conductor paste is sucked through the porous sheet-like body to form the conductive layer in the via hole.

Patent No. 2658414

However, when the green sheet on which the conductive layer is formed is replaced with the next green sheet, if the green sheet is peeled off from the sheet-like body while being sucked, the conductor paste filled by suction becomes the sheet-like body. There was a problem that the remaining part of the green sheet fell out of the via hole and the electrical connection by the via hole could not be established.

An object of the present invention is that when the through hole formed in the base film is filled with the conductive material, the conductive material does not fall out from the through hole even when the conductive material is filled by suction through the porous base material. It is an object of the present invention to provide a method for manufacturing a conductive sheet which can be filled with a conductive material and can be stably electrically connected on both sides.

In order to achieve the above object, in the first invention, a first conductive pattern is formed on one surface of a base film, a first protective film is bonded thereto, and a second conductive pattern is formed on the other surface of the base film. A preparatory step of preparing a protective base material on which a pattern is formed and a second protective film bonded thereto, a step of forming through holes in the protective base material, and a porous base material on the second protective base material. A laminating step, a first coating step of applying the first conductive material on the through hole, a filling step of filling the through hole with the first conductive material by sucking from the porous base material side, and a filling step. After that, a porous base material peeling step of peeling the porous base material without suction, a protective film peeling step of peeling the first protective film and the second protective film, and a first conductive pattern and a first conductive material. , A method for manufacturing a conductive sheet, comprising a second coating step of applying the second conductive material so as to connect the second conductive pattern and the first conductive material, respectively.

With this configuration, after the through hole is filled with the first conductive material, the porous base material is peeled off from the protective base material without suction, so that the conductive material filled in the through hole does not fall out of the through hole. , Both sides of the base film can be stably electrically connected.

The second invention is, in the first invention, the protective film peeling step is the manufacturing method of the conductive sheet which peels off the 1st protective film after peeling off the 2nd protective film.

In this way, after the conductive material is applied and filled, a part of the conductive material remaining on the first protective film is drawn into the through hole when the second protective film is peeled off. Therefore, the conductive material is less likely to fall out of the through hole than when it is peeled off from the first protective film, and both sides of the base film can be stably electrically connected.

In the third aspect of the invention, in the first or second invention, the protective base material and the porous base material are sandwiched between the printing roll and the suction roll provided so as to face the printing roll, and are conveyed. In the coating step, the first conductive material is coated by the printing roll, in the filling step, the first conductive material is filled by suctioning by the suction portion built in the suction roll, and in the porous substrate peeling step, the protecting group is used. This is a method for manufacturing a conductive sheet in which the porous base material is peeled off after the material and the porous base material have passed through the suction portion.

A fourth invention is a method for manufacturing a conductive sheet, wherein the suction portion is provided on the upstream side of a portion where the protective base material and the porous base material are peeled off in the third invention.

With such a configuration, the conductive material can be applied and filled in a large number of through holes at one time by the roll-to-roll method, so that the productivity can be improved.

According to the present invention, it is possible to provide a method for manufacturing a conductive sheet, which can be filled with the conductive material without the conductive material falling out from the through hole and can be stably electrically connected on both sides.

It is a schematic cross-sectional view which shows the manufacturing method of the conductive sheet by 1st Embodiment of this invention. It is a schematic cross-sectional view which shows the manufacturing method of the conductive sheet by 1st Embodiment of this invention. It is a schematic cross-sectional view which shows the manufacturing method of the conductive sheet by 1st Embodiment of this invention. It is a schematic cross-sectional view which shows the manufacturing method of the conductive sheet by 2nd Embodiment of this invention.

Next, an embodiment of the invention will be described with reference to the drawings.
<First Embodiment>

With reference to FIGS. 1 to 3, in the method for manufacturing a conductive sheet 100 according to the first embodiment of the present invention, a first conductive pattern (not shown) is formed on one surface of the base film 1, and the first conductive pattern (not shown) is formed on one surface thereof. A first protective film 3 is bonded to the base film 3, a second conductive pattern (not shown) is formed on the other surface of the base film 1, and a protective base material 10 to which the second protective film 5 is bonded is prepared. A step of forming a through hole 20 in the protective base material 10, a step of laminating the porous base material 30 on the second protective film 5, and a step of applying the first conductive material 40 on the through hole 20. After the first coating step, the filling step of filling the through hole 20 with the first conductive material 40 by sucking from the porous base material 30, and the filling step, the porous base material 30 is peeled off without suction. The porous substrate peeling step, the protective film peeling step of peeling the first protective film 3 and the second protective film 5, the first conductive pattern and the first conductive material 40, and the second conductive pattern and the first conductive material. A second coating step of coating the second conductive material 50 so as to connect to the material 40 is provided.

The material of the base film 1 is not particularly limited as long as it is flexible, and for example, polyesters such as polyethylene terephthalate (PET), polylactic acid (PLA), and polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene. Polyethylenes such as (PP), polystyrene, EVA, cyclic olefin copolymer (COC), vinyl resin, polycarbonate (PC), polyamide, polyimide (PI), acrylic resin (PMMA), triacetyl cellulose (TAC), polyurethane , Silicone, polyvinyl chloride, polyvinyl chloride and other resin films can be used. The lower limit of the thickness of the base film 10 is not particularly limited, but is 5 to 100 μm, preferably 5 to 70 μm.

As the material of the first protective film 3 and the second protective film 5, for example, polypropylene (PP) or polyethylene (PE) can be used, and it is preferable that the material has self-adhesiveness. The lower limit of the thickness of the first protective film 3 and the second protective film 5 is not particularly limited, but is 5 to 50 μm, preferably 5 to 30 μm. The method of bonding the base film 1, the first protective film 3 and the second protective film 5 is not particularly limited, and for example, a laminator can be used.

The through hole 20 is a hole formed so as to penetrate the protective base material 10. Through holes 20 are formed in the base film 1 where the electrode patterns formed on both sides and the routing wiring (not shown) are to be connected. The diameter of the through hole 20 is 5 to 200 μm, preferably 5 to 100 μm.

The material of the porous base material 30 is not particularly limited as long as it is a breathable sheet body, and examples thereof include paper and non-woven fabric. The thickness of the porous substrate 30 is 5 to 200 μm, preferably 5 to 150 μm.

The conductive material 40 is a conductive paste containing a conductive material and a binder. As the conductive material, for example, silver, copper, nickel, gold, tin, bismuth, or alloys thereof can be used. As the binder, a curable resin such as a thermosetting resin or an ultraviolet curable resin can be used.

With reference to FIG. 1A, a first conductive pattern (not shown) is formed on the upper surface of one surface of the base film 1, and the first protective film 3 is attached onto the first conductive pattern. Further, a second conductive pattern (not shown) is formed on the lower surface of the base film 1 which is the other surface, and the second protective film 5 is attached on the second conductive pattern to prepare the protective base material 10. .. The protective base material 10 is laminated in the order of the first protective film 3, the first conductive pattern, the base film 1, the second conductive pattern, and the second protective film 5 from the top.

With reference to FIG. 1 (b), the through hole 20 is formed so as to penetrate the protective base material 10. The through hole 20 can be formed, for example, by irradiating the protective base material 10 with a laser.

With reference to FIG. 1 (c), the porous base material 30 is laminated on the second protective film 5 side of the protective base material 10. The porous base material 30 and the second protective film 5 are laminated only by laminating without using an adhesive or the like.

With reference to FIG. 2A, in the first coating step, the first conductive material 40 is coated on the through holes 20 formed in the protective base material 10. The method of applying the first conductive material 40 is not particularly limited, and examples thereof include screen printing and application by a dispenser.

With reference to FIG. 2B, in the filling step, the first conductive material 40 is filled into the through hole 20 by sucking the first conductive material 40 from the porous base material 30 side. The suction can be performed by a known method such as suction using a vacuum table. The arrows in the figure schematically represent the state of suction. Since the porous base material 30 is made of a material having good air permeability, an attractive force acts on the protective base material 10, and the conductive material 40 is sufficiently filled in the through holes 20.

With reference to FIG. 2C, in the porous base material peeling step, after the filling of the conductive material 40 in the through hole 20 is completed, the porous base material 30 is peeled off without suction. When the porous base material 30 is peeled off, the protective base material 10 in which the through holes 20 are filled with the conductive material 40 is completed.

Next, referring to FIG. 3A, the through hole 20 of the protective base material 10 is filled with the first conductive material 40. At this time, since the first conductive material 40 is applied from above the first protective film 3, the first conductive material 40 is formed so as to protrude from the periphery of the through hole 20 on the first protective film 3. Further, since the porous base material 30 laminated under the second protective film 5 was peeled off, the second protective film 5 and the conductive material 40 filled in the through holes 20 are in a substantially flush state.

With reference to FIG. 3B, in the protective film peeling step, the second protective film 5 is first peeled off. When the second protective film 5 is peeled off, the conductive material 40 is partially pulled into the through hole 20 by being pulled downward, but the conductive material is formed so as to protrude around the through hole of the first protective film 3. The 40 does not get caught and the conductive material 40 does not fall out of the through hole 20.

With reference to FIG. 3C, the first protective film 3 is peeled off after the second protective film 5 is peeled off. Since the conductive material 40 is drawn into the through hole 20 when the second protective film 5 is peeled off, when the first protective film 3 is subsequently peeled off, the conductive material 40 does not come off and the first protective film 3 is peeled off. Can be peeled off.

With reference to FIG. 3D, in the second coating step, the first conductive pattern on the upper surface of the base film 1 and the first conductive material 40 are connected, and the second conductive pattern and the second conductive pattern on the lower surface of the base film 1 are connected. The second conductive material 50 is applied to each of the upper surface and the lower surface of the base film 1 so as to connect the first conductive material 40. The first conductive pattern formed on the upper surface of the base film 1 and the first conductive material 40 are electrically connected by the second conductive material 50, and the second conductive pattern and the first conductive material 40 formed on the lower surface of the base film 1 are further connected. Electrically connecting the Conductive Materials 40 In this way, it is possible to secure the electrical connection between the first conductive pattern and the second conductive pattern formed on both sides of the base film 1.

According to the method for manufacturing a conductive sheet 100 according to the first embodiment of the present invention, the first conductive material 40 is applied to the through hole 20 of the protective base material 10 and is sucked from the porous base material 30 side to be filled. After the completion, the porous base material 30 is peeled off without suction, so that the first conductive material 40 does not fall out of the through hole 20 while adhering to the porous base material 30. Therefore, the conductive material 40 can be stably filled in the through hole 20.

Further, in order to prevent the conductive material 40 from being peeled off from the through hole 20 by peeling from the first protective film 3, the first protective film 3 is peeled off after the second protective film 5 is peeled off. By doing so, it is possible to prevent all the conductive material 40 from falling out from the through hole 20 after filling the conductive material 40.
<Second Embodiment>

Next, with reference to FIG. 4, only the differences between the method of manufacturing the conductive sheet according to the second embodiment of the present invention and the first embodiment will be described.
In the second embodiment, the conductive sheet is manufactured by a roll-to-roll method. The manufacturing apparatus 500 for the conductive sheet 100 includes a printing roll 200 for applying the first conductive material 40, a suction roll 300 provided facing the printing roll 200, and a porous base material 30 toward the suction roll 300. The unwinding roll 310 for unwinding, the winding roll 320 for winding the porous base material 30 that has passed through the suction roll 300, and the first protection for winding the first protective film and the second protective film. A film take-up roll 410 and a second protective film take-up roll 420 are provided.

The protective base material 10 conveyed from the previous step (not shown) is sandwiched between the printing roll 200 and the suction roll 300 and conveyed together with the porous substrate 30 unwound from the unwinding roll 310. To. As a result, the porous base material 30 is laminated on the second protective film 5 side of the protective base material 10.

Next, the first conductive material 40 is applied onto the through holes 20 of the protective base material 10 by the printing roll 200. The printing roll 200 is not limited as long as the first conductive material 40 can be accurately applied onto the through holes 20, and examples thereof include gravure printing, offset printing, and screen printing. Among them, screen printing is preferable because the viscosity of the conductive material 40 is high.

Next, the first conductive material 40 is filled in the through hole 20 by suctioning from the porous base material 30 side with the suction roll 300. The suction roll 300 is provided with a cylindrical inner cylinder having hollow fixed shafts at both ends, an outer cylinder rotatably provided on the outside of both fixed shafts via bearings, and a rotatably provided inside the inner cylinder. It is equipped with an adjustment shaft that can be used. The outer cylinder has a large number of holes formed all around the cylindrical wall. A plurality of suction holes are provided on the cylindrical wall of the inner cylinder. Of the plurality of suction holes, unnecessary suction holes are closed by a member extending in the axial direction. In this way, the suction roll 300 has a built-in suction portion 330 that is composed of a plurality of suction holes and extends in the axial direction.

Specifically, the suction portion 330 of the suction roll 300 is provided upstream from the portion where the porous base material 30 is peeled off from the protective base material 10 in the flow direction of the protective base material 10. That is, the suction portion 330 is provided in front of the portion where the protective base material 10 and the porous base material 30 are peeled off. By doing so, after the conductive material 40 is applied by the printing roll 200, the conductive material 40 is filled by suctioning by the suction portion 330 of the suction roll 300, but the protective base material 10 and the porous base material 30 are filled. No suction was done when peeling. Since the porous base material 30 is peeled off without suction, the first conductive material 40 does not fall out of the through hole 20 while adhering to the porous base material 30. Therefore, the conductive material 40 can be stably filled in the through hole 20.

Next, the second protective film 5 is peeled off by the second protective film winding roll 410, and then the first protective film 3 is peeled off by the first protective film winding roll 420.

According to the method for manufacturing the conductive sheet 1 according to the present embodiment, the conductive material can be applied and filled in a large number of through holes at one time by the roll-to-roll method, so that the productivity is improved. Can be done.

1 Base film 3 1st protective film 5 2nd protective film 10 Protective base 20 Through hole 30 Porous base material 40 1st conductive material 50 2nd conductive material 100 Conductive sheet 200 Printing roll 300 Suction roll 310 Unwinding roll 320 Take-up roll 330 Suction part 410 Second protective film take-up roll 420 First protective film take-up roll

Claims (4)

A first conductive pattern is formed on one surface of the base film, a first protective film is bonded onto the first protective film, a second conductive pattern is formed on the other surface of the base film, and a second protective film is formed on the second conductive pattern. The preparatory process for preparing the bonded protective substrate and
The step of forming a through hole in the protective substrate and
The step of laminating the porous base material on the second protective film and
The first coating step of coating the first conductive material on the through hole, and
A filling step of filling the through hole with the first conductive material by sucking from the porous base material side.
After the filling step, a porous base material peeling step of peeling the porous base material without suction, and a porous base material peeling step.
A protective film peeling step for peeling the first protective film and the second protective film,
A method for manufacturing a conductive sheet, comprising a second coating step of applying a second conductive material so as to connect the first conductive pattern and the first conductive material, and the second conductive pattern and the first conductive material, respectively. .. The method for producing a conductive sheet according to claim 1, wherein the protective film peeling step is a method of peeling the first protective film after peeling the second protective film. The protective base material and the porous base material are sandwiched between a printing roll and a suction roll provided so as to face the printing roll, and are conveyed.
In the first coating step, the first conductive material is coated by the printing roll.
In the filling step, the first conductive material is filled by sucking by a suction portion built in the suction roll, and in the porous base material peeling step, the protective base material and the porous base material are sucked together. The method for producing a conductive sheet according to claim 1 or 2, wherein the porous substrate is peeled off after passing through the portion. The method for manufacturing a conductive sheet according to claim 3, wherein the suction portion is provided on the upstream side of a portion where the protective base material and the porous base material are peeled off.

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