JP2015198108A - Printed wiring board and method of manufacturing the same and photogravure cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress short circuit due to ink, which cannot be scraped by means of a doctor, in a photogravure cylinder for forming the wiring.SOLUTION: A width 31 on at least a part of a corner cavity 30 held between a first bend 11 and a second bend 21 is set larger than a width 33 of a linear cavity 32 between a first straight portion 12 and a second straight portion 22. A width 13 on at least a part of the first bend 11 and second bend 21 is set smaller than a width 14 of the straight portions 12, 22 connected with the bends 11, 21. Even if the ink, that cannot be scraped due to reaction of a doctor 50 flexed in the first groove 10 of a photogravure cylinder, remains in the vicinity of the first groove 10, the risk of occurrence of short circuit of the remaining ink and an adjacent wiring pattern, due to increase in the distance therebetween, can be suppressed.

Description

  The present invention relates to a printed wiring substrate including a printed wiring formed by gravure offset printing or the like, a manufacturing method thereof, and a gravure plate used in gravure offset printing or the like.

  A printed wiring substrate having a printed wiring on a substrate is often used, for example, for an IC card antenna (coiled pattern), a conductive wiring for a solar battery back sheet, an electromagnetic wave shield, a frame wiring for a touch panel, and the like. Among these, for the frame wiring of the touch panel, conventionally, a photolithography method using sputter film formation or a printing method by screen printing is used.

  However, there is a movement to shift from the current manufacturing method to another method due to miniaturization of wiring due to technological innovation and cost competition. For example, in the case of the photolithography method using sputter film formation, the material cost and the process cost are high. Regarding the miniaturization of the wiring, although the wiring width is technically possible up to about 10 μm, the wiring is formed. Since the resistance value of the film is high, there is a possibility that the resistance becomes high when the film is miniaturized. In the case of screen printing, although there is no problem with respect to cost and resistance value, in terms of miniaturization, the width of the wiring is about 80 μm, which is inferior to the photolithography method using sputtering film formation.

  On the other hand, there is a gravure offset printing method as another printing method. For example, Patent Document 1 discloses that gravure offset printing is used as a method for printing a patterned wiring structure on a frame portion in a method for manufacturing a conductive member for a touch panel having a wiring structure.

JP 2011-210148 A

  In gravure offset printing, it is necessary to scrape the ink on the surface with a doctor in order to put ink on the gravure plate and leave ink only in the groove pattern. However, at the bent part of the wiring pattern, if the doctor jumps up due to the reaction that sinks into the groove due to its flexibility, the ink that could not be scraped will remain in the vicinity of the groove, causing a short circuit with the adjacent wiring pattern. May occur. Also, for example, when scraping is performed from the outside of the bent portion so that the longitudinal direction of the doctor is not parallel to any linear groove pattern, the width of the bent portion is relatively close to the contact point with the doctor. Since it becomes large, the problem of a short circuit due to the deflection of the doctor may occur as well.

  Therefore, an object of the present invention is to suppress a short circuit caused by ink that cannot be scraped off by a doctor in a gravure plate for forming a wiring.

The first aspect of the present invention is:
A first corner wiring having a first bent portion and a pair of first straight portions connected to both ends thereof;
A second corner wiring parallel to the inside of the first corner wiring, the second corner wiring having a second bent portion and a pair of second straight portions connected to both ends thereof;
A printed wiring board comprising:
The width of at least a part of at least one of the first bent portion and the second bent portion is made smaller than the width of the straight portion connected to the bent portion,
The width of at least a part of the corner gap portion sandwiched between the first bent portion and the second bent portion is a linear gap portion between the first straight portion and the second straight portion. The printed wiring board is characterized in that it is larger than the width.

  According to this aspect, the width of at least a part of the corner gap portion sandwiched between the first bent portion and the second bent portion is a linear gap between the first straight portion and the second straight portion. The distance between the remaining ink and the adjacent wiring pattern even when ink that has not been scraped off remains in the vicinity of the groove due to the reaction of the doctor bending in the groove. Therefore, the possibility that a short circuit with an adjacent wiring pattern occurs can be suppressed. In addition, since the width of at least a part of at least one of the first bent portion and the second bent portion is smaller than the width of the straight portion connected to the bent portion, a short circuit with an adjacent wiring pattern is prevented. It can suppress more effectively.

Another aspect of the present invention provides:
An imaginary arc connected to the inner periphery of the first straight line centering on the intersection of two normal lines starting from two connection points between the outer peripheral edge of the second bent part and the second straight line part On the other hand, the inner peripheral edge of the first bent portion is deflected outward.

  Another aspect of the present invention is characterized in that the second straight line portion is centered on an intersection of two normal lines starting from two connection points between the outer peripheral edge of the second bent portion and the second straight line portion. The outer peripheral edge of the second bent portion is deflected inward with respect to a virtual arc connected to the outer peripheral edge.

  The first bent portion and the second bent portion may have the same contour shape.

  The printed wiring may be a frame printed wiring of a touch panel.

Another aspect of the present invention provides:
A method for producing a printed wiring board comprising printed wiring,
Filling the groove pattern arranged on the gravure plate with a doctor with ink;
Transferring the ink filled in the groove pattern to a blanket;
A step of transferring the ink transferred to the blanket to a base material to form a printed wiring,
The groove pattern is
A first corner groove having a first bent portion and a pair of first straight portions connected to both ends thereof;
A second corner groove parallel to the inside of the first corner groove, the second corner groove having a second bent portion and a pair of second straight portions connected to both ends thereof;
With
A width of at least a part of at least one of the first bent portion and the second bent portion is made smaller than a width of a straight portion connected to the first bent portion and the second bent portion;
The width of the corner gap portion sandwiched between the first bent portion and the second bent portion is larger than the width of the linear gap portion between the first straight portion and the second straight portion. It is a manufacturing method of the printed wiring board characterized by being made large.

  According to this aspect, the same effect as that of the first aspect can be obtained.

Another aspect of the present invention provides:
A gravure version with a groove pattern,
The groove pattern is
A first corner groove having a first bent portion and a pair of first straight portions connected to both ends thereof;
A second corner groove parallel to the inside of the first corner groove, the second corner groove having a second bent portion and a pair of second straight portions connected to both ends thereof;
With
A width of at least a part of at least one of the first bent portion and the second bent portion is made smaller than a width of a straight portion connected to the first bent portion and the second bent portion;
The width of the corner gap portion sandwiched between the first bent portion and the second bent portion is larger than the width of the linear gap portion between the first straight portion and the second straight portion. It is a gravure version characterized by being considered large.

  According to this aspect, the same effect as that of the first aspect can be obtained.

It is a top view which shows a part of groove pattern arrange | positioned at the gravure plate which concerns on 1st Embodiment. It is a flowchart which shows the manufacturing process of the printed wiring board which concerns on 1st Embodiment. It is a top view which shows a part of printed wiring base material which concerns on 1st Embodiment. It is a top view which shows a part of groove pattern arrange | positioned at the gravure plate which concerns on 2nd Embodiment. It is a top view which shows a part of groove pattern arrange | positioned at the gravure plate which concerns on 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The printed wiring board according to the embodiment of the present invention is a touch panel component, in which frame wiring is formed on a PET film using gravure offset printing.

[Gravure version]
FIG. 1 shows a part of a gravure plate 1 used for gravure offset printing in the production of a printed wiring board according to the first embodiment. The gravure plate 1 has a first groove 10 corresponding to the first corner wiring and a second groove 20 corresponding to the second corner wiring. The gravure plate 1 is made of a copper plate, and after the first groove 10 and the second groove 20 are formed thereon, it is chrome plated.

  The first groove 10 and the second groove 20 are both bent at 90 ° in a plan view and have the same shape in the illustrated region. The second groove 20 is parallel to the inside of the first groove 10.

  The 1st groove | channel 10 has the 1st bending part 11, and a pair of 1st linear parts 12 and 12 connected to the both ends. The 2nd groove | channel 20 has the 2nd bending part 21, and a pair of 2nd linear parts 22 and 22 connected to the both ends. The depth of the first groove 10 and the second groove 20 is 15 μm throughout.

  In a part of the first bent portion 11, the width 13 of the first bent portion 11 is smaller than the width 14 of the first straight portions 12 and 12. Similarly, in a part of the second bent portion 21, the width 13 of the second bent portion 21 is smaller than the width 14 of the second straight portions 22 and 22. The width 13 of the first straight portions 12 and 12 and the width 14 of the second straight portions 22 and 22 are both 50 μm. The widths 13 of the first and second bent portions 11 and 21 are both 25 μm.

  With the outer peripheral edge 23 of the second bent portion 21 and the two connection points 24, 24 between the second straight portions 22, 22 as the center, the first normal 25, 25, the intersection c 2 is the center, the first The inner peripheral edge 18 of the first bent portion 11 is deflected toward the outside of the first bent portion 11 with respect to the virtual arc 17 that continues to the inner peripheral edge 16 of the straight portions 12 and 12. That is, the corner gap 30 sandwiched between the first bent portion 11 and the second bent portion 21 has a region outside the virtual arc 17.

  With the outer peripheral edge 19 of the first bent part 10 and the first straight line parts 12 and 12 as the center, the first normal line 42 and 42 starting from the intersection c1 of the two normals 42 and 42, the first The inner peripheral edge 18 of the first bent portion 11 is deflected toward the outside of the first bent portion 11 with respect to the virtual arc 43 that continues to the inner peripheral edge 16 of the straight portions 12 and 12. That is, the corner gap 30 sandwiched between the first bent portion 11 and the second bent portion 21 has a region outside the virtual arc 43.

  Further, the width 31 of at least a part of the corner gap 30 sandwiched between the first bent portion 11 and the second bent portion 21 is between the first straight portion 12 and the second straight portion 22. It is larger than the width 33 of the linear gap portion 32.

[Method for producing printed wiring substrate]
FIG. 2 is a flowchart showing a method of manufacturing a printed wiring substrate using the gravure plate 1 configured as described above. Below, the method to manufacture a printed wiring base material using the gravure plate 1 which concerns on this embodiment is demonstrated. In FIG. 2, first, the first groove 10 and the second groove 20 of the gravure plate 1 are filled with conductive ink at a constant speed by the doctor 50 (step S10). The linear doctor 50 is in contact with the first groove 10 from the outside of the first bent portion 11 in the direction indicated by the arrow A in the drawing.

  At this time, the doctor 50 is oriented so that the longitudinal direction of the doctor 50 is not parallel to any of the first linear portions 21 and 21. For example, the longitudinal direction of the doctor 50 forms an angle of 15 ° with one first linear portion 21. During this filling, the doctor 50 is made perpendicular to the gravure plate 1. The doctor pressure is 0.5 MPa, and the scraping speed is 10 mm / sec. In FIG. 1, the width (size in the longitudinal direction) of the doctor 50 is shown short for easy understanding, but actually the width of the doctor 50 is a size that covers at least the entire groove pattern of the gravure plate 1. Is set to

  Next, the conductive ink on the gravure plate 1 is transferred onto the blanket (step S20). The blanket is formed by fixing a silicone blanket on the surface of a substantially cylindrical blanket cylinder. The transfer is performed while rotating and moving the blanket cylinder, the pressure is 0.15 MPa, and the rotation speed is 10 mm / sec.

  Next, the conductive ink on the blanket is pressed onto a PET film serving as a base material and transferred (step S30). By this transfer, printed wiring is formed on the PET film. The pressure of the silicone blanket during transfer is 0.15 MPa, the rotational speed is 10 mm / sec, and the thickness of the PET film is 200 μm.

  Next, the ink image printed on the PET film is cured by a heating process (step S40) using a heating means such as an infrared heater.

  The printed wiring board corresponding to the groove pattern of the gravure plate 1 is manufactured by the above manufacturing process. As shown in FIG. 3, the manufactured printed wiring board 60 includes a first corner wiring 70 having a shape corresponding to the first groove 10 and a second corner having a shape corresponding to the second groove 20. Wiring 80.

  Here, as the gravure plate, a copper plate, a metal plate such as a nickel plate, a glass plate, etc. are generally used, but the gravure plate is not limited thereto. In the case of a copper plate, the groove pattern is formed into a required pattern shape by etching. In addition to etching, electroforming, sandblasting, and the like can be given. After the pattern formation, it is preferable to form a rub-resistant film by chromium plating or carbon plating on the surface.

  As a doctor, it is necessary to fill the groove pattern of the gravure plate with ink and to scrape off the ink on the gravure plate. Therefore, the doctor is desirably a metal such as stainless steel, a resin such as urethane, or a ceramic.

  As the ink, various conductive inks such as silver paste and insulating resin inks can be used.

  Silicon is generally used as the material of the layer formed on the surface of the cylindrical cylinder of the blanket, but is not limited thereto.

  Of the manufacturing method of the printed wiring substrate described above, in the step of filling the gravure plate 1 with the conductive ink (step S10), the longitudinal direction of the doctor 50 does not seem to be parallel to any of the first linear portions 21 and 21. Oriented. Therefore, compared to the case where the longitudinal direction of the doctor 50 is parallel to one of the two first straight portions 21, the sinking of the doctor 50 with respect to the first groove 10 is suppressed. However, the length 51 in which the doctor 50 contacts the substantially arc-shaped first groove 10 and the second groove 20 is larger than the width 14 of the first straight portion 12 of the first groove 10. Therefore, in the vicinity of the 1st bending part 11, it is inevitable that the doctor 50 sinks into the 1st groove | channel 10 by the flexibility, and jumps up by the reaction.

  However, according to the present embodiment, the width 31 of a part of the corner gap 30 sandwiched between the first bent portion 11 and the second bent portion 21 is equal to the first straight portion 12 and the second straight portion. Since the width of the linear gap portion 32 between the portions 22 is larger than the width 33, the ink that has not been scraped off by the reaction of the doctor 50 in the first groove 10 is removed from the first gravure plate 1. Also when remaining in the vicinity of the groove 10, the distance between the remaining ink and the adjacent wiring pattern becomes larger, and the possibility that a short circuit between the adjacent wiring pattern occurs can be suppressed. Moreover, since the width 13 of a part of the first bent portion 11 and the second bent portion 21 is smaller than the width 14 of the straight portions 12 and 22 connected to the bent portions 11 and 21, adjacent wirings Short circuit with the pattern can be more effectively suppressed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the first embodiment, the inner peripheral edge 18 of the first bent portion 11 and the inner peripheral edge of the second bent portion 21 are deflected outward, respectively, so that a part of the width 13 of the first bent portion 11 is made. It was made smaller than the width 14 of the first straight portions 12 and 12. In contrast, in the second embodiment, as shown in FIG. 4, the outer peripheral edges 119 and 123 of the first bent portion 11 and the second bent portion 21 are deflected inward, respectively. is there.

  In FIG. 4, centering on an intersection c101 of two normal lines 142, 142 starting from two connection points 141, 141 between the outer peripheral edge 119 of the first bent portion 111 and the first straight portions 112, 112. The outer peripheral edge 119 of the first bent portion 111 is deflected inward with respect to the virtual arc 153 that is continuous with the outer peripheral edge of the first straight portion 112. The inner peripheral edge 118 of the first bent portion 111 is on a ¼ virtual imaginary circumference centering on the intersection c101.

  Similarly, the second normal line 125, starting from the two connection points 124, 124 between the outer peripheral edge 123 of the second bent part 121 and the second straight line parts 122, 122 is centered on the intersection c102. The outer peripheral edge 123 of the second bent portion 121 is deflected inward with respect to a virtual arc 163 that continues to the outer peripheral edge of the second straight portion 120. The inner peripheral edge 128 of the second bent portion 121 is on a ¼ virtual imaginary circumference centering on the intersection c102.

  The corner gap 130 sandwiched between the first bent portion 111 and the second bent portion 121 has a region outside the virtual arc 117 and a region inside the virtual arc 163.

  Since the remaining configuration in the second embodiment is the same as that in the first embodiment, a reference numeral obtained by adding 100 to the reference numeral in the first embodiment is attached, and the detailed description thereof is omitted. A printing method using the gravure plate 101 according to the second embodiment is the same as that of the first embodiment. Since the printed wiring board manufactured using the gravure plate 101 has a simple mirror surface with the gravure plate 101, the illustration thereof is omitted. According to the gravure plate 101 configured as described above, a short circuit between adjacent wiring patterns can be more effectively suppressed.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the third embodiment, as shown in FIG. 5, the inner peripheral edge 218 of the first bent portion 211 and the inner peripheral edge 228 of the second bent portion 221 are deflected outward, respectively, and the first bent portion 211 and outer peripheral edges 219 and 223 of the second bent portion 221 are deflected inward.

  In FIG. 5, the shape of the inner peripheral edge 219 of the first bent portion 211 is the same as that of the inner peripheral edge 18 in the first embodiment. The shape of the inner peripheral edge 223 of the second bent portion 221 is the same as the inner peripheral edge 28 in the first embodiment.

  Moreover, the shape of the outer periphery 219 of the 1st bending part 211 is the same as that of the outer periphery 119 in the said 2nd Embodiment. The shape of the outer peripheral edge 223 of the second bent portion 221 is the same as the outer peripheral edge 123 in the second embodiment.

  Since the remaining configuration in the third embodiment is the same as that in the first embodiment or the second embodiment, a code obtained by adding 200 to the code in the first embodiment or 100 added to the code in the second embodiment. Reference numerals are assigned and detailed description thereof is omitted. The printing method using the gravure plate 201 according to the third embodiment is the same as that of the first embodiment. Since the printed wiring board manufactured using the gravure plate 201 has a simple mirror surface with the gravure plate 201, its illustration is omitted. According to the gravure plate 201 configured as described above, a short circuit between adjacent wiring patterns can be more effectively suppressed.

  The present invention is not limited to the scope of each of the above-described embodiments, and modifications such as design changes can be added based on the knowledge of those skilled in the art. Can also be included in the scope of the present invention. For example, the first bent portion and the second bent portion may have different contour shapes. Any one of the first corner wirings of the first, second, and third embodiments and any one of the second corner wirings of the first, second, and third embodiments can be combined into a single You may combine on a printed wiring board. Three or more grooves may be provided in parallel on the gravure plate, and three or more corner wirings may be arranged in parallel on the printed wiring substrate.

  One of the first bent portion and the second bent portion is any one of the first corner wirings of the first, second, and third embodiments, or the first, second, and third embodiments. The second corner wiring may be an arbitrary one, and the other may be a bent portion before improvement according to the present invention (that is, one having a uniform width over its entire length).

  The width of the first bent portion and / or the second bent portion may be made smaller than the width of the straight portion connected to the bent portion over the entirety thereof. The width of the corner gap portion may be larger than the width of the straight gap portion over the whole.

  The printed wiring board of the present invention is a combination of a means for filling ink in a fine groove pattern corresponding to a doctor and an intaglio in which a fine groove pattern corresponding to a gravure plate is arranged. It is particularly preferable that the ink is formed by a printing method in which excessive scraping of ink in the groove pattern due to the presence of a groove pattern parallel to the length direction of a doctor is a problem. Examples of such a printing method include gravure offset printing, direct gravure printing, pad printing, and the like. However, the printed wiring board of the present invention may be manufactured by a printing method other than gravure offset printing.

  The printed wiring board of the present invention is particularly preferably used as a frame wiring for a touch panel in terms of application to fine wiring. However, in addition to this, it can be used in many cases, for example, for IC card antennas (coiled patterns), conductive wiring of solar battery back sheets, electromagnetic wave shields, and the like, and such applications also belong to the category of the present invention.

1, 101, 201 Gravure plates 10, 110, 210 First grooves 17, 117, 217 Virtual arcs 18, 118, 218 connected to the inner peripheral edge Inner peripheral edges 19, 119, 219 of the first groove Outside the first groove Periphery 20, 120, 220 Second groove 23, 123, 223 Second groove outer periphery 28, 128, 228 Second groove inner periphery 50 Doctor 60 Printed wiring substrate 70 First corner wiring 80 Second Corner wirings 163, 263 of virtual arcs c1, c2, c101, c102, c201, c202 intersecting with the outer periphery

Claims (7)

A first corner wiring having a first bent portion and a pair of first straight portions connected to both ends thereof;
A second corner wiring parallel to the inside of the first corner wiring, the second corner wiring having a second bent portion and a pair of second straight portions connected to both ends thereof;
A printed wiring board comprising:
The width of at least a part of at least one of the first bent portion and the second bent portion is made smaller than the width of the straight portion connected to the bent portion,
The width of at least a part of the corner gap portion sandwiched between the first bent portion and the second bent portion is a linear gap portion between the first straight portion and the second straight portion. A printed wiring board characterized by being larger than the width. The printed wiring board according to claim 1,
An imaginary arc connected to the inner periphery of the first straight line centering on the intersection of two normal lines starting from two connection points between the outer peripheral edge of the second bent part and the second straight line part On the other hand, the printed wiring board is characterized in that the inner peripheral edge of the first bent portion is deflected outward. The printed wiring board according to claim 1,
A virtual arc connected to the outer peripheral edge of the second straight line centering on the intersection of two normal lines starting from two connection points between the outer peripheral edge of the second bent part and the second straight line part On the other hand, a printed wiring board characterized in that an outer peripheral edge of the second bent portion is deflected inward. The printed wiring board according to claim 1,
The printed wiring substrate, wherein the first bent portion and the second bent portion have the same contour shape.   The printed wiring substrate according to any one of claims 1 to 3, wherein the printed wiring is a frame printed wiring of a touch panel. A method for producing a printed wiring board comprising printed wiring,
Filling the groove pattern arranged on the gravure plate with a doctor with ink;
Transferring the ink filled in the groove pattern to a blanket;
A step of transferring the ink transferred to the blanket to a base material to form a printed wiring,
The groove pattern is
A first corner groove having a first bent portion and a pair of first straight portions connected to both ends thereof;
A second corner groove parallel to the inside of the first corner groove, the second corner groove having a second bent portion and a pair of second straight portions connected to both ends thereof;
With
A width of at least a part of at least one of the first bent portion and the second bent portion is made smaller than a width of a straight portion connected to the first bent portion and the second bent portion;
The width of the corner gap portion sandwiched between the first bent portion and the second bent portion is larger than the width of the linear gap portion between the first straight portion and the second straight portion. A method for producing a printed wiring substrate, characterized in that the printed wiring substrate is large. A gravure version with a groove pattern,
The groove pattern is
A first corner groove having a first bent portion and a pair of first straight portions connected to both ends thereof;
A second corner groove parallel to the inside of the first corner groove, the second corner groove having a second bent portion and a pair of second straight portions connected to both ends thereof;
With
A width of at least a part of at least one of the first bent portion and the second bent portion is made smaller than a width of a straight portion connected to the first bent portion and the second bent portion;
The width of the corner gap portion sandwiched between the first bent portion and the second bent portion is larger than the width of the linear gap portion between the first straight portion and the second straight portion. A gravure version characterized by being considered large.

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