JP5398339B2 - Method for forming fine line pattern and gravure printing machine for forming fine line pattern - Google Patents

Description

  The present invention relates to a fine line pattern forming method and a gravure printing machine for forming a fine line pattern. In the present invention, the fine line pattern means a pattern composed of lines (fine lines) having a line width of 1 to 60 μm, and the figure and dimensions of the pattern are not limited.

  In recent years, in order to reduce the layout space by integrating electronic equipment components at high density, for example, from the request to make the external dimensions of electronic equipment products such as mobile phones compact, the line width of fine line patterns has been increasingly reduced, There is a need for a fine line pattern with a narrow wiring pitch. Also, in the fine line pattern forming method, environmental measures and cost reduction measures are becoming increasingly important.

Conventionally, conductive fine line patterns have been used for various electronic device components. For example, fine line patterns are used in the following fields (Patent Documents 1 to 9).
(1) A mesh pattern made of a conductive metal as an electromagnetic wave shielding material for shielding electromagnetic waves from various displays such as CRT and plasma display (PDP) (Patent Documents 1 to 3).
(2) A wiring circuit pattern of a flexible printed wiring board (FPC) (Patent Documents 4 and 5).
(3) A graphic pattern for frequency selective shielding of the electromagnetic wave absorber and a mesh pattern made of a conductive metal forming a reflective layer. (Patent Documents 6 and 7).
(4) Antenna circuit pattern of RFID tag (Patent Documents 8 and 9).

On the other hand, the following method is mentioned as the formation method of the fine line pattern currently disclosed by patent documents 1-9.
(A) An etching method that forms various fine line patterns by etching a metal foil by a photolithography method (Patent Documents 1, 4, and 6).
(B) A printing method in which various fine line patterns are formed by printing a conductive paste (Patent Documents 2, 3, 5, 7 to 9).

As shown above, the fields in which fine line patterns are used include conductive mesh patterns of electromagnetic shielding materials for displays such as PDPs, conductive mesh patterns of transparent conductive materials, wiring circuit patterns of flexible printed wiring boards, and electromagnetic waves. These include a graphic pattern for selecting the frequency of the absorber, a mesh pattern made of a conductive metal forming a reflective layer, and an antenna circuit pattern of an RFID tag.
The present invention relates to a fine line pattern forming method and a gravure printing machine for forming a fine line pattern, which can be applied to these fields.

In FPC that has been used for electronic devices for a long time, a method for forming a wiring circuit pattern has been mainly a method of etching a copper foil by photolithography (Patent Document 4). The line width of the FPC wiring circuit pattern by the etching method was about 20 to 50 μm.
In the conventional etching method, there are problems that the cost for drainage measures is high, and that the waste of metal increases when the distance between the lines becomes larger than the line width. For this reason, as a method for forming an FPC wiring circuit pattern, a printing method in which a wiring circuit pattern is formed by screen-printing a conductive paste is employed as an alternative to the etching method (Patent Document 5). In addition, the line width of the wiring circuit pattern by screen printing is about 60-200 micrometers.

  For this reason, it is thought that the printing system which prints an electrically conductive paste and forms a fine line pattern instead of an etching system is also one of the advantageous methods. As a method for forming a fine line pattern by a printing method, a screen printing method using a screen printing machine and a gravure printing method using a gravure rotary printing machine or a gravure rotary offset printing machine are mainly mentioned.

  By the way, the screen printing method (see, for example, Patent Document 10) uses a stencil that has the same principle as a copy-printed plate that has existed for a long time, and applies and cures an adhesive on a fine mesh made of metal or resin. An opening hole pattern through which the conductive paste is removed is formed, and the conductive paste is extruded from the opening hole pattern by pushing down the conductive paste from above the screen plate with a squeegee (having a function like a brush). Thus, a fine line pattern is formed on the substrate.

In the screen printing method, the accuracy of the line width of the fine line pattern is determined by the accuracy of finishing the opening width of the opening hole pattern, and it is difficult to reduce the line width formed by the screen printing method to about 60 μm or less. Has been. In particular, in the screen printing method, it is very difficult to make the line width about 40 μm or less.
Recently, in various fields using the above fine line pattern, it is required to make the line width 60 μm or less, and it is becoming difficult to cope with the screen printing method. In addition, the normal screen printing method has a problem that printing productivity is low because printing is performed by fixing an object to be printed under a screen plate and printing cannot be performed continuously. It was.

In this regard, the gravure printing method uses a gravure rotary printing press or a gravure rotary offset printing press, and continuously rotates the gravure cylinder around which the gravure plate is wound and the impression cylinder pressed against the gravure plate. In addition, since the fine line pattern can be formed, the productivity is higher than the screen printing method and the printing method has an advantage.
However, the present inventors have tried to form a fine line pattern by a conventionally known gravure printing method, but have found various problems. As a result of studies to solve the problems of these gravure printing methods, the present invention has been completed.

JP 2000-98912 A JP 2004-172288 A JP 2003-304090 A Japanese Patent Application Laid-Open No. 5-74861 JP-A-10-117055 JP 2003-258487 A JP-A-6-85532 JP 2003-223626 A JP-T-2004-529499 JP-A-8-300615

  In the formation of the fine line pattern by the above etching method (a), only a very small part that becomes a thin line part is left by etching, and most of the other metals are dissolved and removed from the viewpoint of saving resources. It is a problem. In addition, the etching method has a problem that the waste liquid processing cost increases.

  The formation of the fine line pattern by the printing method (b) is a resource-saving and more preferable method for forming the fine line pattern than the etching method (a). In particular, the gravure printing method using the above gravure rotary printing press is capable of continuous printing as compared to the screen printing method, and can be manufactured in a roll-to-roll manner, so that it is highly productive. It is a forming method.

  In the field related to the formation of a mesh pattern made of a conductive metal as an electromagnetic wave shielding material for shielding electromagnetic waves from various displays such as CRT and plasma display (PDP) disclosed in Patent Documents 1 to 3, etching is performed. A method (Patent Document 1), an intaglio offset printing system (Patent Document 2), and a gravure printing system (Patent Document 3) are used.

  Patent Document 1 discloses an etching method. Copper deposited on the surface of polyethylene terephthalate (PET) film with copper of 5000 angstroms (500 nm), and an etching resist is formed in a lattice pattern (line width 25 μm, line interval 250 nm), and is not covered with resist. Etching is performed and finally the resist is removed to form a fine line pattern. As described above, according to the etching method, it is possible to form a fine line pattern having a line width of 50 μm or less. However, as described above, there are problems of measures against drainage.

  Patent Document 2 discloses an intaglio offset printing method as an example. It is assumed that a glass intaglio is used for printing, and a stripe pattern having a line width of 50 μm and a line interval of 200 μm is formed. The intaglio offset printing method using a glass intaglio can form a fine line pattern with a line width of 50 μm or less. However, as with the screen printing method described above, continuous printing cannot be performed, so productivity is low. Has the problem.

In Patent Document 3, a resin composition containing a plating catalyst is printed by a gravure printing method to form a net-like fine line pattern having an average line width of 50 μm or less, and then the fine line pattern is subjected to electroless plating. It is disclosed that metal layers are stacked to increase conductivity.
Patent Document 3 relates to formation of a fine line pattern having a line width of 50 μm or less by a gravure printing method, but does not directly obtain a final fine line pattern by printing a conductive paste by a gravure printing method. Further, no specific details of the gravure rotary printing press are disclosed.

Patent Documents 4 and 5 relating to the field of wiring circuit patterns of flexible printed circuit boards disclose an etching method and a screen printing method, respectively.
In Patent Document 4, regarding the etching method, when a wiring pattern is formed by etching, etching is performed after processing a commercially available metal foil to a thickness that can maintain strength according to the fineness of the wiring pattern. A copper foil with a thickness of 18 μm is appropriate for a wiring pattern pitch of 50 μm (line width 25 μm, line spacing 25 μm). For this reason, in the formation of the fine line pattern by the etching method, there is a problem that it takes time and effort in addition to the above drainage countermeasures.

  Patent Document 5 describes that the conductive pattern is formed by screen printing with a line width of 150 μm and a line interval of 150 μm. As described above, the screen printing method has a problem that productivity is low because continuous printing cannot be performed.

Patent Documents 6 and 7 relating to a graphic pattern for selecting a frequency of an electromagnetic wave absorber and a mesh pattern made of a conductive metal forming a reflective layer disclose an etching method and a screen printing method, respectively.
Patent Document 6 discloses that an electromagnetic wave shielding body that absorbs or reflects a predetermined frequency is formed by an antenna pattern using an aggregate of conductors having a width of 50 μm or less by an etching method. However, the formation of the fine line pattern by the etching method has the problem of the above-mentioned drainage countermeasure.

  Patent Document 7 discloses that in a λ / 4 type electromagnetic wave absorber having a resistor and a reflector, the resistor is formed by a resistor paste that is screen-printed in an arbitrary pattern. Although it is described that printing was performed by a screen printing method with a grid pattern having a line width of 2.65 mm, a space of 7.35 mm, and a thickness of 10 μm, the screen printing method has a problem that productivity is low because continuous printing cannot be performed. doing.

Patent Documents 8 and 9 relating to antenna circuit patterns of RFID tags disclose a screen printing method and a gravure printing method, respectively.
Patent Document 8 discloses that an antenna pattern is formed by a screen printing method of conductive ink in a method of manufacturing an RFID tag including an antenna pattern and an IC chip. Although it is described that the screen printing is performed so that the antenna width is 250 μm and the thickness is 10 μm, the screen printing method has a problem that productivity is low because continuous printing cannot be performed as described above.

Patent Document 9 discloses that a carrier of a fine line pattern is formed by a gravure printing method using a conductive ink, and then the carrier is plated to form a fine line pattern serving as an antenna. .
In the gravure printing method, a track width (line width) of about 100 μm and a width between tracks of about 100 μm can be obtained.
Patent Document 9 relates to formation of a fine line pattern having a line width of about 100 μm by a gravure printing method, but does not directly obtain a final fine line pattern by printing a conductive paste by a gravure printing method. . Furthermore, no specific details of the gravure rotary printing press are disclosed.

  The present invention has been made in view of the above circumstances, and is a method for forming a fine line pattern in consideration of environmental problems, and has a higher productivity than the screen printing method, and a method for forming a fine line pattern, Another object of the present invention is to provide a gravure printing machine for forming a fine line pattern.

In order to solve the above problems, the present invention contains one or more selected from the group of conductive fillers consisting of conductive metal particles, carbon nanotubes, and carbon nanofibers on one surface of a flexible substrate. the conductive paste is a method of forming a fine line pattern with a line width 1～60Myuemu, the thickness of the fine line pattern to be formed is 1 to 10 [mu] m, the surface of the gravure cylinder of a gravure printing machine A conductive paste is press-fitted with a doctor blade into the mold groove of the fine line pattern of the formed gravure plate, and a reservoir of the conductive paste is provided at an acute angle portion formed by the doctor blade and the gravure cylinder, The acute angle portion holds an angle of 40 to 70 degrees, and is 45 to 180 degrees clockwise or counterclockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder. Performs line contact between the transfer material and the gravure cylinder at location, the transfer material is a flexible substrate holding was to the gravure cylinder and the impression cylinder, said from the gravure plate at the line contact position There is provided a method for forming a fine line pattern, wherein the conductive paste is transferred to a transfer material.

Also, the fine line pattern, the conductive mesh pattern of electromagnetic wave shielding material for PDP, the conductive mesh pattern of the transparent conductive material, the wiring circuit pattern of the flexible printed circuit board, and figure patterns for frequency selection of the electromagnetic wave absorber It is preferably one selected from the group consisting of a mesh pattern made of a conductive metal forming the reflective layer and an antenna circuit pattern of the RFID tag.

In order to solve the above problems, the present invention provides at least one selected from the group of conductive fillers composed of conductive metal particles, carbon nanotubes, and carbon nanofibers on one surface of a flexible substrate. Is a gravure printing machine that forms a fine line pattern with a line width of 1 to 60 μm using a conductive paste containing the gravure printing machine , and the gravure printing machine has a thickness of 1 to 10 μm, A conductive paste is press-fitted with a doctor blade into a mold groove of a fine line pattern of a gravure plate formed on the surface of the cylinder, and the storage part of the conductive paste is an acute angle part formed by the doctor blade and the gravure cylinder And the acute angle portion holds an angle of 40 to 70 degrees, and is 4 clockwise or counterclockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder. At 5 to 180 degree position performs line contact between the transfer material and the gravure cylinder, wherein the transfer material is a flexible substrate holding was to the gravure cylinder and the impression cylinder, at the line contact position providing a gravure printing machine of the fine line pattern formation characterized by comprising disposed so as to transfer the conductive paste to the transfer material from the gravure plate.

Also, the gravure printing machine is preferably a rotogravure printing machine.

  According to the present invention, the conductive mesh pattern of the electromagnetic shielding material for PDP, the conductive mesh pattern of the transparent conductive material, the wiring circuit pattern of the flexible printed wiring board, the graphic pattern for frequency selection of the electromagnetic wave absorber, and the reflection layer are provided. A fine line pattern such as a mesh pattern made of conductive metal to be formed, an antenna circuit pattern of an RFID tag, etc., using a highly productive gravure printing method and gravure rotary printing machine, line width 1 to 1 made of conductive paste A fine line pattern of 60 μm can be formed.

In the gravure rotary printing press for fine line pattern formation by this invention, it is the schematic conceptual diagram which showed one example of the relative positional relationship of a gravure cylinder and a transfer material. In the gravure rotary offset printing press for fine line pattern formation by this invention, it is the schematic conceptual diagram which showed one example of the relative positional relationship of a gravure cylinder and a transfer material. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 1st example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 2nd example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 3rd example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 4th example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 5th example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 6th example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 7th example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. In the gravure rotary printing press for fine line pattern formation by this invention, it is a schematic conceptual diagram which shows the 8th example of the relative positional relationship of a gravure cylinder, an impression cylinder, and a doctor blade. FIG. 4 is a partial detail view of part A in FIG. 3. In the gravure rotary printing press for fine line pattern formation by this invention, it is explanatory drawing which shows the angle range C of the transfer position in a gravure cylinder which can transfer an electrically conductive paste from a gravure plate to a flexible base material. is there. In the formation method of the fine line pattern by this invention, it is explanatory drawing which shows the angle range D in a gravure drum | blade which can attach a doctor blade. It is a conceptual diagram which shows the principle of a screen printing system. (A) is a schematic conceptual diagram which shows the relative positional relationship of the gravure cylinder, impression cylinder, ink cylinder, and doctor blade in the gravure rotary printing press by a prior art, (b) is a part of B section of (a) FIG. 2 is a photomicrograph showing an appearance photograph of a conductive mesh pattern of an electromagnetic wave shielding material for PDP formed in Example 1. FIG. 5 is a photomicrograph showing an appearance photograph of a conductive mesh pattern of an electromagnetic wave shielding material for PDP formed in Comparative Example 1. FIG. 6 is a micrograph showing an external appearance photograph of a conductive mesh pattern of an electromagnetic wave shielding material for PDP formed in Comparative Example 2. FIG. 4 is a photomicrograph showing an appearance photograph of a conductive mesh pattern of an electromagnetic wave shielding material for PDP formed in Example 2. FIG.

The present invention will be described below based on preferred embodiments with reference to the drawings.
FIG. 1 is a schematic conceptual view showing an example of a relative positional relationship between a gravure cylinder and a transfer material in a gravure rotary printing press for forming a fine line pattern according to the present invention.
In a gravure rotary printing press 10 for forming a fine line pattern shown in FIG. 1, a conductive paste 8 is pressed into a mold groove of a fine line pattern of a gravure plate formed on the surface of a gravure cylinder 1 by a doctor blade 7. Further, in accordance with the rotation of the gravure cylinder 1 and the impression cylinder 2, the flexible base material 3 is fed out while being guided in the transfer direction by the guide rolls 4, 4. It is held between the impression cylinders 2.
The conductive paste 8 supplied to the gravure cylinder 1 is transferred to the flexible substrate 3 by the rotation of the gravure cylinder 1.

FIG. 2 is a schematic conceptual diagram showing an example of the relative positional relationship between the gravure cylinder and the transfer material in the gravure rotary offset printing press for fine line pattern formation according to the present invention.
In the gravure rotary offset printing press 100 shown in FIG. 2, a conductive paste 8 is press-fitted by a doctor blade 7 into a mold groove of a fine line pattern of a gravure plate formed on the surface of a gravure cylinder 1. In addition, a transfer roll 101 having flexibility to contact the gravure cylinder 1 is provided between the gravure cylinder 1 and the impression cylinder 2. In accordance with the rotation of the transfer roll 101 and the impression cylinder 2, the flexible base 3 is fed out while being guided in the transfer direction by the guide rolls 4 and 4, and the flexible base 3 is transferred to the transfer roll 101 and the impression cylinder. It is held between two.
The conductive paste 8 supplied to the gravure cylinder 1 is transferred to the transfer roll 101 by the rotation of the gravure cylinder 1 and further transferred to the flexible substrate 3 by the rotation of the transfer roll 101.

  In the case of the gravure rotary printing press 10, the transfer material onto which the conductive paste 8 is transferred from the gravure plate 1 is the flexible substrate 3. In the case of a gravure rotary offset printing press, the transfer material onto which the conductive paste 8 is transferred from the gravure plate 1 is a transfer roll 101. In any case, the line contact between the gravure cylinder 1 and the transfer material 3, 101 is performed at a position of an angle α from the upper end when viewed from the rotation axis direction of the gravure cylinder 1 shown in FIGS. At the position, the conductive paste 8 is transferred from the gravure plate to the transfer material 3,101. The angle α is preferably within a range of 45 to 180 degrees clockwise or counterclockwise from the upper end.

  Moreover, it is preferable that the storage part of the electroconductive paste 8 is provided in the acute angle part which the doctor blade 7 and the gravure cylinder 1 make, and an acute angle part hold | maintains the angle (beta) of 40-70 degree | times. 1 and 2, the doctor blade 7 is in contact with the longitudinal direction B of the doctor blade 7 and the outer peripheral surface of the gravure cylinder 1 in a cross section perpendicular to the central axis of the gravure cylinder 1 as shown in FIGS. It means the angle made with the tangent T at the position.

The gravure printing press for forming a fine line pattern according to the present invention includes a gravure rotary printing press or a gravure rotary offset printing press, but the difference between the two is only the transfer material, and the essential technical idea. Are the same.
Therefore, in the following description, only the gravure rotary printing press will be described in order to avoid duplication of explanation, but it can be easily replaced with a gravure rotary offset printing press for understanding.

  FIG. 3 shows a first example of the relative positional relationship between the gravure cylinder 1, the impression cylinder 2, and the doctor blade 7 in the gravure rotary printing press 10A for fine line pattern formation according to the present invention. In accordance with the rotation of the gravure cylinder 1 and the impression cylinder 2, the flexible base 3 is fed out while being guided in the transfer direction by the guide rolls 4 and 4. In FIG. 3, line contact is made between the gravure cylinder 1 and the flexible substrate 3 held by the impression cylinder 2 at a position of 45 degrees clockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1. The conductive paste 8 is transferred from the gravure plate to the flexible substrate 3. The rotation direction of the gravure cylinder 1 is counterclockwise, and the flexible substrate 3 is fed upward from the lower side of the impression cylinder 2.

  As shown in FIG. 11 which is a partial detailed view of part A in FIG. 3, the blade 5 of the doctor blade 7 is pressed against the gravure plate 11 disposed on the surface of the gravure cylinder 1, and the surface of the gravure plate 11 The conductive paste 8 is press-fitted into the mold groove 12 formed in the above. The conductive paste 8 is supplied by a dispenser 18, is sandwiched between the doctor blade 7 and the gravure cylinder 1, and is stored in an acute angle portion formed by the doctor blade 7 and the gravure cylinder 1. The blade 5 of the doctor blade is held by a doctor blade holder 6. The gravure plate 11 is formed on the surface of the gravure cylinder 1, and the mold groove 12 of the gravure plate 11 is formed in a pattern corresponding to the fine line pattern transferred to the flexible substrate 3.

  The conductive paste 13 press-fitted into the mold groove 12 is transferred to the flexible substrate 3 when it comes into contact with the flexible substrate 3. In FIG. 3, the doctor blade 7 (specifically, the blade 5) is in contact with the gravure cylinder 1 at a position of 45 degrees counterclockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1. Further, the attachment position of the doctor blade 7 indicated by a two-dot chain line in FIG. 3 is one of the modified examples, and the doctor blade 7 is positioned 90 degrees counterclockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1. In contact with the gravure cylinder 1 at.

  FIG. 4 shows a second example of the relative positional relationship between the gravure cylinder 1, the impression cylinder 2, and the doctor blade 7 in the gravure rotary printing press 10B for fine line pattern formation according to the present invention. In this example, line contact between the gravure cylinder 1 and the flexible substrate 3 held by the impression cylinder 2 is performed at a position of 135 degrees clockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1. The conductive paste 8 is transferred from the gravure plate to the flexible substrate 3. The rotation direction of the gravure cylinder 1 is counterclockwise, and the flexible substrate 3 is fed upward from the lower side of the impression cylinder 2. The doctor blade 7 contacts the gravure cylinder 1 at a position of 45 degrees counterclockwise (indicated by a solid line) or 90 degrees (indicated by a two-dot chain line) as viewed from the rotation axis direction of the gravure cylinder 1. ing.

  FIG. 5 shows a third example of the relative positional relationship between the gravure cylinder 1, the impression cylinder 2, and the doctor blade 7 in the gravure rotary printing press 10C for fine line pattern formation according to the present invention. In this example, line contact between the gravure cylinder 1 and the flexible substrate 3 held by the impression cylinder 2 is performed at a position of 135 degrees clockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1. The conductive paste 8 is transferred from the gravure plate to the flexible substrate 3. The rotation direction of the gravure cylinder 1 is clockwise, and the flexible substrate 3 is drawn out from the upper side to the lower side of the impression cylinder 2. The doctor blade 7 is in contact with the gravure cylinder 1 at a position of 45 degrees clockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1.

  FIG. 6 shows a fourth example of the relative positional relationship between the gravure cylinder 1, the impression cylinder 2, and the doctor blade 7 in the gravure rotary printing press 10D for fine line pattern formation according to the present invention. In this example, line contact between the gravure cylinder 1 and the flexible substrate 3 held by the impression cylinder 2 is performed at a position 180 degrees clockwise from the upper end when viewed from the rotation axis direction of the gravure cylinder 1. The conductive paste 8 is transferred from the gravure plate to the flexible substrate 3. The rotation direction of the gravure cylinder 1 is counterclockwise, and the flexible substrate 3 is fed out from the left side of the impression cylinder 2 to the right side. The doctor blade 7 contacts the gravure cylinder 1 at a position of 45 degrees counterclockwise (indicated by a solid line) or 90 degrees (indicated by a two-dot chain line) as viewed from the rotation axis direction of the gravure cylinder 1. ing.

  FIGS. 7 to 10 show gravure rotary presses 10E, 10F, 10G, and 10H for fine line pattern formation according to the present invention, in the same manner as described above, the gravure cylinder 1, the impression cylinder 2 and the doctor blade 7 of the gravure rotary press. It is the 5th-8th example which showed these relative positional relationships. The transfer position of the conductive paste 8 from the gravure plate to the flexible substrate 3 and the contact position between the doctor blade 7 and the gravure cylinder 1 are different. Specifically, FIG. 7 shows the positional relationship of FIG. 6 reversed left and right, and FIGS. 8 to 10 show the positional relationship of FIGS.

  FIG. 12 shows the range C of the transfer position on the gravure cylinder in which the conductive paste can be transferred from the gravure plate to the flexible substrate 3 in the gravure rotary printing press for fine line pattern formation according to the present invention. It is explanatory drawing shown. The transferable angle range C in the gravure cylinder 1 is a position of 45 to 180 degrees clockwise or counterclockwise from the upper end 16 when viewed from the rotation axis direction of the gravure cylinder 1. In the present invention, line contact is made between the gravure cylinder 1 and the flexible substrate 3 held by the impression cylinder 2 within the above angle range C, and the conductive paste is transferred from the gravure plate to the flexible substrate 3. Is displayed to be transferred.

  FIG. 12 shows a set of configurations in which the flexible base material 3 is held by the gravure cylinder 1 and the impression cylinder 2 (the position of the doctor blade is omitted), as well as in the angle range C described above. Another example of the position where the impression cylinder 2 can be disposed is shown by a two-dot chain line. FIG. 12 shows a position of about 45 degrees, about 90 degrees, or about 135 degrees clockwise from the upper end 16 of the gravure cylinder 1, and about 45 degrees, about 90 degrees, or about about 90 degrees counterclockwise from the upper end 16 of the gravure cylinder 1. The example in which the impression cylinder 2 is disposed at a position of 135 degrees or a position of the lower end 17 of the gravure cylinder 1 (that is, 180 degrees clockwise and counterclockwise from the upper end 16) is shown. It is not necessary to be arranged in the other direction, and it is possible to arrange it at other angular positions such as about 60 degrees or about 120 degrees clockwise or counterclockwise.

  FIG. 13 is an explanatory view showing an angle range D in a gravure cylinder to which a doctor blade can be attached in the fine line pattern forming method according to the present invention. The angle range D in which the doctor blade 7 can be attached to the gravure cylinder 1 shown in FIG. 13 is at a position of 0 to 135 degrees clockwise or counterclockwise from the upper end 16 when viewed from the rotation axis direction of the gravure cylinder 1. The blade 5 of the doctor blade 7 and the gravure cylinder 1 are brought into contact with each other, and the conductive paste 8 is formed by the blade 5 of the doctor blade 7 in the mold groove 12 of the fine line pattern formed on the gravure plate 11 as shown in FIG. Is displayed to be press-fitted.

  FIG. 13 shows a set of configurations in which the conductive paste 8 is stored in the acute angle portion formed by the gravure cylinder 1 and the doctor blade 7 (the position of the impression cylinder is omitted), as well as the angle range described above. Another example of the position where the doctor blade 7 in D can be attached is shown by a two-dot chain line. FIG. 13 shows a position of about 45 degrees, about 90 degrees, or about 135 degrees clockwise from the upper end 16 of the gravure cylinder 1, and about 45 degrees, about 90 degrees, or about counterclockwise from the upper end 16 of the gravure cylinder 1. The example in which the doctor blade 7 is attached at a position of 135 degrees or at the position of the upper end 16 of the gravure cylinder 1 (ie, 0 degrees clockwise and counterclockwise from the upper end 16) is a multiple of 45 degrees or its vicinity. It is not necessary and can be mounted at other angular positions, such as about 60 degrees or about 120 degrees clockwise or counterclockwise.

FIG. 14 is a conceptual diagram showing the principle of the screen printing method.
The screen printing machine 20 shown in FIG. 14 uses a screen plate 26 in which an opening hole pattern 29 through which ink 25 is removed is formed by applying and curing an adhesive on a metal or resin fine wire mesh. While holding the squeegee holder 22 by hand and moving the squeegee 23, the ink 25 is pressed against the screen plate 26 by the blade 21 of the squeegee so that the ink 25 is extruded from the aperture pattern 29 and printed on the substrate 24. Ink 27 adheres to form a fine line pattern.
In the screen printing method, the accuracy of the line width of the fine line pattern is determined by the accuracy of finishing the opening width of the opening hole pattern 29. When a highly viscous conductive paste is used, the line formed by the screen printing method is used. It is considered difficult to make the width about 60 μm or less. In addition, the screen printing method has a drawback in that a fine line pattern cannot be formed continuously on a long flexible substrate, and thus a fine line pattern cannot be formed with increased productivity. Yes.

FIG. 15A is a schematic conceptual diagram showing the relative positional relationship of the gravure cylinder 31, the impression cylinder 32, the ink cylinder 39, and the doctor blade 37 in the gravure rotary printing press 30 according to the prior art, and FIG. FIG. 16 is a partial detail view of a portion B in FIG.
As shown in FIG. 15 (b), the surface of the gravure cylinder 31 has a fine line pattern mold groove 42 formed on a gravure plate 41 made of a laminated copper plating layer.
In a conventional gravure rotary printing press 30 according to the prior art, a printing ink having a low viscosity is used. Therefore, even at a printing speed of several hundred meters / minute, the gravure plate 41 is pushed into the mold groove 42 by the doctor blade 37. The press-in of the ink 38 and the transfer of the ink 38 from the mold groove 42 to the flexible substrate 33 are sufficiently performed. However, it has been found that it is inappropriate to use a conductive paste having a low viscosity in order to form a fine line pattern having a line width of 1 to 60 μm.

  On the other hand, the conductive paste used in the gravure rotary printing presses 10A to 10H for forming a fine line pattern according to the present invention is for forming a fine line pattern having a line width of 1 to 60 μm, and is therefore used for normal gravure printing. Higher viscosity than printing ink. Therefore, when the conductive paste 8 is press-fitted into the mold groove 12 of the gravure plate 11 by the doctor blade 7 and when the conductive paste 8 is transferred from the mold groove 12 to the flexible substrate 3, Since the flow of the conductive paste 8 is very slow and slow, the flow deformation of the conductive paste cannot follow the conventional printing speed.

Also, if the gravure cylinder is rotated at such a speed that the conductive paste in the mold groove of the gravure plate is spun off by centrifugal force, the conductive paste becomes concave in the mold groove and the central part is depressed, and the flexibility When the conductive paste is transferred to the base material, a phenomenon occurs in which the central portion is cut and disconnected.
Therefore, in order to form a fine line pattern having a line width of 1 to 60 μm, it is necessary to transfer the conductive paste in the mold groove to the flexible substrate at a speed slower than the printing speed of the prior art. . Therefore, in the conventional gravure rotary printing press 30 according to the prior art, the printing speed is usually several hundred meters / minute, and the conductive paste in the mold groove is flexed by utilizing the centrifugal force accompanying the rotation of the gravure cylinder. The gravure rotary printing presses 10A to 10H for forming a fine line pattern according to the present invention, while being transferred to a conductive substrate, have a printing speed significantly slowed down to several meters / minute.

  In the gravure rotary printing presses 10A to 10H for fine line pattern formation of the present invention, as shown in FIG. 12, the angle range C that can be transferred by the gravure cylinder 1 is viewed from the rotation axis direction of the gravure cylinder 1, Line contact is made between the gravure cylinder 1 and the flexible substrate 3 held by the impression cylinder 2 at a position of 45 to 180 degrees clockwise or counterclockwise from the upper end 16, and the groove 12 is formed by the action of gravity. The inside conductive paste 13 (see FIG. 11) is devised so as to be easily discharged.

As shown in FIG. 15A, in the gravure rotary printing press 30 according to the prior art, the printing ink 38 is transferred to the flexible substrate 33 at the position of the upper end when viewed from the rotation axis direction of the gravure cylinder 31. Yes. As in the present invention, a line between the gravure cylinder and the flexible substrate held by the impression cylinder at a position of 45 to 180 degrees clockwise or counterclockwise from the upper end as viewed from the rotation axis direction of the gravure cylinder. Contact is not made and the conductive paste is not transferred from the gravure plate to the flexible substrate.
Further, the ink 38 contained in the ink storage tank 40 is poured into the mold groove 42 of the fine line pattern formed on the gravure plate 41 laminated on the gravure cylinder 31 via the ink cylinder 39, and the gravure plate 41. Excess ink adhering to the ink is scraped off by the blade 35 of the doctor blade 37. The doctor blade 37 used in the gravure rotary printing press 30 according to the prior art includes a doctor blade blade 35 and a doctor blade holder 36.

With respect to the orientation of the doctor blade, in the conventional gravure rotary printing press 30 shown in FIG. 15, the tip of the blade 35 of the doctor blade is inclined upward, and excess ink 38 adhering to the gravure cylinder 31 is below the blade 35 of the doctor blade. Scratched to the side. However, in this method, in order to collect the ink 38 that falls, an ink storage tank 40 is disposed below the gravure cylinder 31 and an ink cylinder 39 for lifting the ink 38 from the ink storage tank 40 to the gravure cylinder 31 is required. become. In the present invention, as shown in FIG. 13, the doctor blade 7 desirably has the tip of the blade 5 directed downward from the horizontal, so that the sharp angle portion formed by the gravure cylinder 1 and the doctor blade 7 is electrically conductive. The paste 8 is stored by gravity.
In order to prevent the fine lines printed using the conductive paste from being chipped, it is necessary to press the conductive paste with a suitable pressure into the mold groove of the fine line pattern of the gravure plate with a suitable pressure. For this, it is preferable that the acute angle portion formed by the gravure cylinder 1 and the doctor blade 7 maintains an angle β of 40 to 70 degrees.
Furthermore, the conductive paste 8 stored in the doctor blade 7 and the new conductive paste 8 dispensed from the upper part are disposed by making the cutting edge downward as much as possible within a range that does not hinder the dispensing of the conductive paste 8 from above. However, rolling of the gravure cylinder 1 is likely to occur on the doctor blade 7, and the conductive paste 8 is always kneaded during printing, so that even the minimum storage amount can be stored on the doctor blade 7 without an ink tank. As a result, the conductive paste 8 is hardly altered and continuous printing can be performed stably. In the present invention, the direction of the tip of the blade 5 of the doctor blade 7 is preferably in the range of 90 degrees on the left side to 90 degrees on the right side with the downward direction as the center. A range from 70 degrees on the left side to 70 degrees on the right side is more preferable.

(Flexible substrate)
The material of the flexible substrate 3 used in the present invention is selected according to the application of the fine line pattern to be formed.
For example, a conductive mesh pattern of an electromagnetic shielding material incorporated in an optical filter for PDP, a conductive mesh pattern of a transparent conductive material, a graphic pattern for frequency selection of a transparent electromagnetic wave absorber, and a conductive metal forming a reflective layer For applications that require optical transparency, such as a mesh pattern, it is preferable to have transparency in the visible region and generally have a total light transmittance of 90% or more. Especially, the resin film which has flexibility is used suitably at the point which is easy to handle. Specific examples of transparent resin films used for transparent substrates include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic resins, epoxy resins, fluororesins, silicone resins, polycarbonate resins, and diacetates. Single-layer film having a thickness of 20 to 300 μm made of resin, triacetate resin, polyarylate resin, polyvinyl chloride, polysulfone resin, polyether sulfone resin, polyimide resin, polyamide resin, polyolefin resin, cyclic polyolefin resin, or the transparent resin A multi-layer composite film consisting of

  Moreover, the wiring circuit pattern of the flexible printed circuit board (FPC) does not require the transparency of the flexible base material, but for applications that require heat resistance of 300 ° C. or higher, polyimide (PI) having excellent heat resistance. ) Resin film is mainly used. The polyimide film is preferable in that it has heat resistance, can sufficiently withstand the soldering temperature at the time of component mounting, and can exhibit stable performance against environmental changes after being actually incorporated into a device. The thickness of the flexible base material 3 for FPC is usually 12.5 to 50 μm.

  Moreover, the antenna thin wire pattern of the RFID tag does not require transparency of the flexible base material, and does not require heat resistance of 300 ° C. or more unlike the flexible printed wiring board. The flexible base material 3 used for the antenna thin wire pattern of the RFID tag is paper such as fine paper, glassine paper, coated paper, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyphenylene sulfide. (PPS), polyolefin resins such as polyethylene and polypropylene, synthetic resins such as polyvinyl chloride resins, polyurethane resins, acrylic resins, and fluorine resins, etc., but these are laminated films using one or more of these. May be. The thickness of the flexible substrate 3 for use in RFID tags is usually 20 to 300 μm, and is used as a single layer film or a multi-layer composite film.

  On the surface of the flexible substrate (the surface on the side that receives the conductive paste), the substrate is treated with corona discharge, plasma treatment, ozone treatment, flame treatment, primer (anchor coating, adhesion promotion) as an easy adhesion treatment. (Also referred to as an agent or an easy-adhesive agent), pre-heat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, and the like may be performed.

(Fine line pattern)
In the present invention, a conductive paste is press-fitted by a doctor blade into a mold groove of a fine line pattern of a gravure plate formed on the surface of a gravure cylinder of a gravure rotary printing press, and the gravure cylinder and the impression cylinder are pressed against each other. The conductive paste is transferred from the gravure plate to the flexible substrate at the position where the line contact with the flexible substrate is performed, whereby a fine line pattern is formed on the flexible substrate.
When forming a seamless (seamless) fine line pattern mold groove on the gravure plate formed on the surface of the gravure cylinder, by using the gravure plate and conductive paste, for example, to a continuous film An electromagnetic wave shielding material for PDP made of a continuous conductive mesh pattern without joints can be manufactured.
The gravure plate is preferably composed of a copper plating layer laminated on the surface of the gravure cylinder and a surface hardened layer of either chromium plating or DLC thin film (Diamond-Like Carbon) laminated on the copper plating layer. .
In addition to etching using photoresist and photomask, engraving with a diamond needle at the tip (electronic engraving) is used to form a fine line pattern groove on a gravure plate consisting of a copper plating layer. Alternatively, a method of etching after forming a resist pattern by laser irradiation is used. In particular, the latter method of etching after laser irradiation is preferably used as a method of forming a fine mold groove. The surface hardened layer can be formed by an appropriate known technique.

In the present invention, the pattern of the fine line pattern having a line width of 1 to 60 μm formed by the conductive paste is selected according to the use of the fine line pattern to be formed.
For example, in a conductive mesh pattern of an electromagnetic wave shielding material for PDP incorporated in an optical filter for PDP, a fine line pattern is formed in a lattice shape having a line width of 1 to 60 μm and a pitch interval of 200 to 350 μm. The thickness of the fine line pattern is affected by the conductive performance of the conductive paste used, but is about 2 to 10 μm.
Further, in the conductive mesh pattern of the transparent conductive material, the fine line pattern is formed in a lattice shape having a line width of 10 to 60 μm and a pitch interval of 200 to 1000 μm. The thickness of the fine line pattern is influenced by the conductive performance of the conductive paste used, but is about 0.5 to 10 μm.
Also, in the printed circuit pattern of the flexible printed circuit board, there are round and square soldering lands provided around the surface of the hole for inserting the through-hole mounting component, and a square footprint for mounting the surface mounting component. A fine line pattern is formed in which conductors are connected vertically and horizontally with a line width of 5 to 50 μm and a pitch interval of about 10 to 100 μm between vertical and horizontal dimensions of about 0.35 to 0.55 mm. . The thickness of the fine line pattern is affected by the conductive performance of the conductive paste used, but is about 1 to 10 μm.

The graphic pattern for selecting the frequency of the electromagnetic wave absorber is, for example, a circular or quadrangular annular graphic pattern formed with a line width of 1 to 60 μm and arranged two-dimensionally. The size of the graphic pattern is the length corresponding to the wavelength of the electromagnetic wave to be shielded by the entire circumference of the graphic, and is about 3 cm for an electromagnetic wave of 10 GHz, for example.
The line width is very small compared to the size of the figure pattern because it is not visible to humans if the line width is about 60 μm or less, so it is not visible even if an electromagnetic wave absorber film is attached to a window glass etc. Will have sex. Further, the mesh pattern made of a conductive metal that forms the reflection layer of the electromagnetic wave absorber is also a lattice shape having a line width of 1 to 60 μm and a pitch interval of 200 to 350 μm, like the conductive mesh pattern of the electromagnetic wave shielding material for PDP. A fine line pattern is formed.

  In addition, as the antenna fine line pattern of the RFID tag, an antenna fine line pattern in which a thin line is wound a plurality of times into a coil shape is used. Current general RFID tag antennas do not require transparency. In order to reduce manufacturing costs, an RFID tag antenna having a frequency of 13.56 MHz is formed with a fine line pattern having a line width of about 0.1 to 0.5 mm. In the future, an RFID tag antenna aimed at ultra-miniaturization in a frequency band of 2.45 GHz is required to have a line width of about 30 to 50 μm. According to the present invention, it is possible to form an antenna fine line pattern having such a fine line width.

(Conductive paste)
As the conductive paste used in the present invention, a conductive paste obtained by mixing a conductive filler with a resin component serving as a binder is usually used.
The conductive paste preferably contains one or more selected from the group of conductive fillers composed of conductive metal particles, carbon nanotubes, and carbon nanofibers. As the conductive metal particles, metal powders such as copper, silver, nickel, and aluminum are used. From the viewpoint of conductivity and cost, it is preferable to use copper or silver fine powder. In addition, carbon nanotubes and carbon nanofibers that are conductive carbon nanoparticles can also be used.

Since the line width of the fine line pattern formed by printing is about 1 to 60 μm, the particle diameter of the conductive metal particles is preferably 0.05 to 1 μm. For example, in a condition where the line width of the printed thin line is as narrow as 1 to 60 μm and the thickness of the thin line is as thin as 2 to 10 μm, it is difficult to increase the conductivity if the particle diameter of the metal particles is larger than 1 μm. . In general, it is desirable that the particle diameter of the metal particles is a size of 1/20 or less than the line width of the mold groove of the fine line pattern of the gravure plate.
When it is necessary to eliminate the metallic luster of the fine line pattern formed by printing and suppress reflection of external light, it is preferable to mix a black pigment such as carbon black. The black pigment is preferably contained at 0.1 to 10% by weight in the conductive paste.

  As the resin component serving as a binder used in the conductive paste, a thermoplastic resin such as a polyester resin, a (meth) acrylic resin, a polyethylene resin, a polystyrene resin, or a polyamide resin is preferably used. Moreover, thermosetting types, such as an epoxy resin, an amino resin, a polyimide resin, (meth) acrylic resin, may be sufficient.

  The conductive paste is mixed with conductive resin particles such as conductive metal particles, carbon nanotubes, carbon nanofibers, and black pigment in these resin components, and then an organic solvent such as alcohol or ether is added as necessary. Adjust the viscosity. The conductive paste used in the present invention preferably has a higher viscosity than printing ink used for ordinary gravure printing. The viscosity can be adjusted by the addition amount (blending ratio) of the organic solvent. Further, during continuous printing, in order to prevent the viscosity of the organic solvent from volatilizing due to the volatilization of part of the organic solvent from the conductive paste in the reservoir of the conductive paste of the doctor blade, or the conductivity of the reservoir In order to return the viscosity to an appropriate range after the viscosity of the paste is increased, and when a new ink is supplied on the plate, the trace remains on the printed product. When the conductive paste is added to the conductive paste, it is preferable to supply a conductive paste having a composition obtained by diluting the conductive paste first supplied onto the storage portion of the conductive paste with an organic solvent.

In order to confirm the effect of the present invention, a conductive mesh pattern of an electromagnetic wave shielding material for PDP was formed using a gravure rotary printing press for forming a fine line pattern based on the present invention.
(Measuring device, measuring method)
Various physical property values of the formed conductive mesh pattern were measured by the following measuring apparatus and measuring method.

(Appearance observation and pattern line width measuring device, measuring method)
Appearance observation and pattern line width measurement were performed using a digital microscope (manufacturer: Keyence Corporation, model: VHX-500).
(Pattern line thickness measuring device, measuring method)
The line thickness of the formed conductive mesh pattern was measured using a contact type three-dimensional measuring device (manufacturer: Tokyo Seimitsu Co., Ltd., model: Surfcom 1900DX).
(Printing speed measuring device, measuring method)
The printing speed of the conductive mesh pattern by the gravure rotary printing machine was performed using a tachometer (manufacturer: Ono Sokki Co., Ltd., model: HT-341).

(Surface resistivity measuring device, measuring method)
The surface resistivity of the formed conductive mesh pattern was measured using a resistivity meter (manufacturer: Mitsubishi Chemical Corporation, model: Lorester GP MCP-T600).
The measuring method was performed based on JIS K7194, “Resistivity Test Method of Conductive Plastic by Four-Probe Method”.

(Transmittance measuring device, measuring method)
The transmittance of the formed conductive mesh pattern was measured using a haze meter (manufacturer: Nippon Denshoku Industries Co., Ltd., model: NDH2000).
The measuring method was performed based on JIS K7361-1, “Plastic—Testing method of total light transmittance of transparent material—Part 1: Single beam method”.

(Haze measuring device, measuring method)
The haze value of the formed conductive mesh pattern was measured using a haze meter (manufacturer: Nippon Denshoku Industries Co., Ltd., model: NDH2000).
The measuring method was performed based on JIS K7136, “Plastic—How to determine haze of transparent material”.

Example 1
As the flexible substrate, a substrate having a thickness of 100 μm and a coating agent that quickly absorbs the solvent component of the ink was used on a polyethylene terephthalate (PET) resin film subjected to corona treatment as an easy adhesion treatment.
As the fine line pattern of the gravure plate, the line width of the mold groove is 20 μm, the target pattern thickness after drying is about 2 μm, the depth of the mold groove is a constant value in the range of 5 to 30 μm, and the pitch interval of the grating A gravure plate having a lattice-like mesh pattern with a thickness of 300 μm was prepared. Using a gravure rotary printing press equipped with the prepared gravure plate, printing was performed using a conductive paste containing silver particles as a conductive metal.
The gravure rotary printing machine used was arranged with a gravure cylinder, an impression cylinder, and a doctor blade in a positional relationship close to that shown in FIG. 4 (the doctor blade is attached by a two-dot chain line). That is, the angle of attachment of the doctor blade is 56.5 degrees from below, and the blade edge of the doctor blade is gravure at a position 90 degrees counterclockwise from the upper end of the gravure cylinder as viewed from the rotation axis direction of the gravure cylinder. Touched the plate. In this case, the angle β of the acute angle portion formed by the doctor blade and the gravure cylinder is 56.5 degrees.
The transfer position is such that line contact is made between the gravure cylinder and the flexible substrate pressed by the impression cylinder at a position of 130 degrees clockwise from the upper end of the gravure plate as viewed from the rotation axis direction of the gravure cylinder. Arranged.
The printing speed was 5.0 m / min. After printing, drying was performed at 130 ° C. for 5 minutes to obtain a transparent electromagnetic shielding material.

(Comparative Example 1)
Transparent electromagnetic wave shield in the same manner as in Example 1 except that the contact position of the blade of the doctor blade with the plate at the rotation axis of the gravure cylinder is 100 degrees counterclockwise from the upper end of the gravure cylinder. The material was obtained.

(Comparative Example 2)
In order to set the transfer position to the same transfer position as the gravure printing method in the prior art, as shown in FIG. A transparent electromagnetic wave shielding material was obtained under the same conditions as in Example 1 except that it was arranged so as to be in line contact with the flexible substrate held by the substrate.

(Example 2)
A transparent electromagnetic wave shielding material was obtained under the same conditions as in Example 1 except that a flexible base material without a coating agent was used.

  Table 1 shows the results of measuring various physical property values of the formed conductive mesh pattern for the PDP electromagnetic shielding film of each test example thus obtained.

16 to 19 are photomicrographs showing appearance photographs of conductive mesh patterns of the electromagnetic shielding material for PDP formed by Example 1, Comparative Example 1, Comparative Example 2, and Example 2, respectively.
In the micrograph (FIG. 16) of Example 1 according to the present invention, a good fine line pattern with a substantially constant line width is obtained.
In contrast to Example 1 according to the present invention, in Comparative Example 1, since the ink on the doctor is filled in the plate pattern at the upper position, the filling property is lowered, and the printed fine line is broken ( FIG. 17) In addition, since the doctor faces upward as compared to Example 1, the kneading property of the paste on the doctor is lowered, and the ink is locally dried and cured, so that the ink left on the plate is not scraped off. It tends to occur.
Compared to Example 1 according to the present invention, in Comparative Example 2 (FIG. 18) in which the transfer position is the same as that of the gravure rotary printing press in the prior art, the transfer amount of the conductive paste is reduced, so that the formed electromagnetic shielding material The surface resistivity is about 20% higher.
In contrast to Example 1 according to the present invention, in Example 2, the same conditions as in Example 1 are applied except that an absorbent coating agent is not applied to the base material. Although the total light transmittance is reduced by about 4%, the surface resistivity is not so different because the amount of ink being transferred is equivalent to that in Example 1. Moreover, compared with the comparative examples 1 and 2 which apply | coated the coating agent which has an absorptivity to a base material, Example 2 is excellent in surface resistivity. This is considered to be an effect of arrangement on the gravure cylinder.

According to the present invention, there is provided a fine line pattern forming method in consideration of environmental problems and a highly productive fine line pattern forming method compared with a screen printing method, and a gravure printing machine for forming a fine line pattern. Is done.
Using the fine line pattern forming method of the present invention and the gravure printing machine for forming the fine line pattern, the conductive mesh pattern of the electromagnetic shielding material for PDP, the conductive mesh pattern of the transparent conductive material, and the flexible printed wiring board Wiring circuit patterns, graphic patterns for frequency selection of electromagnetic wave absorbers, mesh patterns made of conductive metal forming a reflective layer, antenna fine line patterns of RFID tags, etc. can be formed, which is very beneficial for industry. It is.

DESCRIPTION OF SYMBOLS 1,31 ... Gravure cylinder, 2,32 ... Impression cylinder, 3,33 ... Flexible base material, 4,34 ... Guide roll, 5,35 ... Doctor blade blade, 6,36 ... Doctor blade holder, 7, 37 ... Doctor blade, 8 ... Conductive paste, 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H ... Gravure rotary printing press for fine line pattern formation, 11, 41 ... Gravure plate, 12, 42 DESCRIPTION OF SYMBOLS 13: Press-fit conductive paste, 15 ... Backup plate, 16 ... Upper end of gravure cylinder, 17 ... Lower end of gravure cylinder, 20 ... Screen printer, 21 ... Squeegee blade, 22 ... Squeegee holder, 23 ... squeegee, 24 ... substrate, 25 ... ink, 26 ... screen plate, 27 ... printed ink, 28 ... weir, 29 ... aperture pattern, 30 ... conventional glue Via rotary printing press, 38 ... ink, 39 ... ink cylinder, 40 ... ink tank, 100 ... gravure rotary offset printing press for fine line patterning, 101 ... transfer roll.

Claims (4)

On one surface of the flexible substrate, the conductive metal particles, carbon nanotubes, a conductive paste one or more selected from among conductive filler group consisting of carbon nanofibers are contained, line width 1 A method of forming a fine line pattern of ˜60 μm, wherein the fine line pattern to be formed has a thickness of 1 to 10 μm, and a fine line pattern mold of a gravure plate formed on the surface of a gravure cylinder of a gravure printing machine A conductive paste is press-fitted into the groove with a doctor blade, and a reservoir for the conductive paste is provided at an acute angle portion formed by the doctor blade and the gravure cylinder, and the acute angle portion has an angle of 40 to 70 degrees. holding it in, and, when viewed from the axial direction of the gravure cylinder, the line between the gravure cylinder and the transfer material at a position of 45 to 180 degrees clockwise or counterclockwise from the upper end It performs contact, the transfer material, wherein a flexible substrate holding was gravure cylinder and the impression cylinder, to transfer the conductive paste to the transfer material from the gravure at the line contact position A feature of forming a fine line pattern. The fine line pattern includes a conductive mesh pattern of an electromagnetic shielding material for PDP, a conductive mesh pattern of a transparent conductive material, a wiring circuit pattern of a flexible printed wiring board, a graphic pattern for frequency selection of an electromagnetic wave absorber, and a reflective layer. 2. The method of forming a fine line pattern according to claim 1 , wherein the fine line pattern is selected from the group consisting of a mesh pattern made of a conductive metal to be formed and an antenna circuit pattern of an RFID tag. On one surface of the flexible substrate, the conductive metal particles, carbon nanotubes, a conductive paste one or more selected from among conductive filler group consisting of carbon nanofibers are contained, line width 1 A gravure printing machine for forming a fine line pattern of ˜60 μm, wherein the thickness of the fine line pattern to be formed is 1 to 10 μm, and the fine line pattern of the gravure plate formed on the surface of the gravure cylinder of the gravure printing machine The conductive paste is press-fitted into the mold groove with a doctor blade, the conductive paste reservoir is provided at an acute angle portion formed by the doctor blade and the gravure cylinder, and the acute angle portion is 40 to 70 degrees. it holds the angle, and the gravure cylinder in viewed from the rotation axis direction, the gravure cylinder and the rolling at a position of 45 to 180 degrees clockwise or counterclockwise from the upper end Performs linear contact with Utsushizai, the transfer material, wherein a flexible substrate which is holding the gravure cylinder and the impression cylinder, the conductive paste from the gravure plate at the line contact position to the transfer material A gravure printing machine for forming a fine line pattern, wherein the gravure printing machine is arranged so as to transfer the ink. The gravure printing machine, a gravure printing press for fine line patterning of claim 3, characterized in that the gravure rotary press.